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clinical articles • management advice • practice profiles • technology reviews Spring 2017 – Vol 10 No 1



The benefits and limitations of CBCT Dr. Alix Davies


ENDODONTICS Risk assessment of endodontic-related nerve injuries: part 2

Plateletrich fibrin in endodontics Dr. Edward S. Lee

Practice profile Dr. Michael A. Miyasaki

Endodontics and implantology: odd couple or opposites attract? Jordan Reiss




Dr. Tara Renton


Patients Want to Keep Their Real Tooth. In a 2016 study published in JOE,1 patients named tooth retention as a top priority, second only to trust and communication about treatment options.

Patients Want to Avoid A Root Canal. Consumers have feared the idea of standard RCT for decades. The result? Patients and providers alike are opting for implant-supported crown replacement instead of RCT.

Patients Want an RCT Alternative. Enter the GentleWave® Procedure—a minimally invasive, single-appointment procedure that delivers a higher standard of clean throughout the root canal system2—and a lower chance of failure3 that can result in tooth extraction.

Talk to Sonendo® about the GentleWave® System today. Make the real difference for your patients and the economy of your practice. Visit

Debris left behind after standard RCT*

A higher standard of clean with the GentleWave Procedure*

VISIT US AT AAE! APRIL 26-29 | NEW ORLEANS | BOOTH #649 * 1000x magnification 1 Azarpazhooh A et al. (2016) J Endod. 42:365-370 2 Molina B et al. (2015) J Endod. 41:1701-5 3 Sigurdsson A et al. (2016) J Endod. 42:1040-48 © 2017 Sonendo, Inc. All rights reserved. SONENDO, the SONENDO logo, GENTLEWAVE, the GENTLEWAVE logo, and SOUND SCIENCE are trademarks of Sonendo, Inc. Patented: MM-0308 Rev 01

ASSOCIATE EDITORS Julian Webber, BDS, MS, DGDP, FICD Pierre Machtou, DDS, FICD Richard Mounce, DDS Clifford J Ruddle, DDS John West, DDS, MSD EDITORIAL ADVISORS Paul Abbott, BDSc, MDS, FRACDS, FPFA, FADI, FIVCD Professor Michael A. Baumann Dennis G. Brave, DDS David C. Brown, BDS, MDS, MSD L. Stephen Buchanan, DDS, FICD, FACD Gary B. Carr, DDS Arnaldo Castellucci, MD, DDS Gordon J. Christensen, DDS, MSD, PhD B. David Cohen, PhD, MSc, BDS, DGDP, LDS RCS Stephen Cohen, MS, DDS, FACD, FICD Simon Cunnington, BDS, LDS RCS, MS Samuel O. Dorn, DDS Josef Dovgan, DDS, MS Tony Druttman, MSc, BSc, BChD Chris Emery, BDS, MSc. MRD, MDGDS Luiz R. Fava, DDS Robert Fleisher, DMD Stephen Frais, BDS, MSc Marcela Fridland, DDS Gerald N. Glickman, DDS, MS Kishor Gulabivala, BDS, MSc, FDS, PhD Anthony E. Hoskinson BDS, MSc Jeffrey W Hutter, DMD, MEd Syngcuk Kim, DDS, PhD Kenneth A. Koch, DMD Peter F. Kurer, LDS, MGDS, RCS Gregori M. Kurtzman, DDS, MAGD, FPFA, FACD, DICOI Howard Lloyd, BDS, MSc, FDS RCS, MRD RCS Stephen Manning, BDS, MDSc, FRACDS Joshua Moshonov, DMD Carlos Murgel, CD Yosef Nahmias, DDS, MS Garry Nervo, BDSc, LDS, MDSc, FRACDS, FICD, FPFA Wilhelm Pertot, DCSD, DEA, PhD David L. Pitts, DDS, MDSD Alison Qualtrough, BChD, MSc, PhD, FDS, MRD RCS John Regan, BDentSc, MSC, DGDP Jeremy Rees, BDS, MScD, FDS RCS, PhD Louis E. Rossman, DMD Stephen F. Schwartz, DDS, MS Ken Serota, DDS, MMSc E Steve Senia, DDS, MS, BS Michael Tagger, DMD, MS Martin Trope, BDS, DMD Peter Velvart, DMD Rick Walton, DMD, MS John Whitworth, BchD, PhD, FDS RCS CE QUALITY ASSURANCE ADVISORY BOARD Dr. Alexandra Day, BDS, VT Julian English, BA (Hons), editorial director FMC Dr. Paul Langmaid, CBE, BDS, ex chief dental officer to the Government for Wales Dr. Ellis Paul, BDS, LDS, FFGDP (UK), FICD, editor-inchief Private Dentistry Dr. Chris Potts, BDS, DGDP (UK), business advisor and ex-head of Boots Dental, BUPA Dentalcover, Virgin Dr. Harry Shiers, BDS, MSc (implant surgery), MGDS, MFDS, Harley St referral implant surgeon © FMC 2017. All rights reserved. FMC is part of the specialist publishing group Springer Science+Business Media. The publisher’s written consent must be obtained before any part of this publication may be reproduced in any form whatsoever, including photocopies and information retrieval systems. While every care has been taken in the preparation of this magazine, the publisher cannot be held responsible for the accuracy of the information printed herein, or in any consequence arising from it. The views expressed herein are those of the author(s) and not necessarily the opinion of either Orthodontic Practice US or the publisher.

Volume 10 Number 1

Endodontic Revolution: “Get your root canals won!”


t is a great time to be in the field of endodontics. In the past 10 years, there has been a technological revolution of new products that has served to make endodontics more effective, efficient, and excellent (E3 Endodontics). The revolution heated up when cone beam computed tomography (CBCT) was introduced. The CBCT has completely changed the way we practice and treatment plan. We are now able to threedimensionally visualize the number and location of canals and roots, unusual anatomy, and any bony pathology prior to access. During a procedure, the operator can also take a CBCT to help locate a calcified canal. Reid V. Pullen, DDS New nickel-titanium metallurgy has greatly improved the endodontic game and has given practitioners a way to shape canals safely, easily, and efficiently. The WaveOne® Gold (Dentsply Sirona) reciprocating file can shape an entire root canal system with just one file. This was completely unheard of 6 years ago and blew my mind when it was first introduced. In fact, I initially said, “You can’t do that.” Now we have heat-treated nickel-titanium — called gold wire, blue wire, M-wire, etc. — that makes the shaping files much more resistant to cyclic fatigue and thus more resistant to file separation. I believe when a practitioner uses these new and improved nickel-titanium files, they take out a file-separation insurance policy. Yes, separation can happen, but it takes a lot of work to separate these types of shaping files. New calcium silicate sealers such as bioceramic sealer (BC Sealer™, Brasseler USA®), BioRoot™ RCS (Septodont), and ProRoot™ ES (Dentsply Sirona) have allowed efficient, biocompatible sealing of the root canal system with exceptionally less postoperative discomfort (and, yes, they are retreatable if gutta percha is used). These sealers serve as both a sealer and a filler and can be used in a warm vertical, single-cone, or obturator/obturation method. Not only has shaping and sealing improved, but the chemical debridement revolution is on. We started with standard needle irrigation introducing bleach into the pulp chamber and canals. Since then we have learned that, due to trapped air, a vapor lock can form at the root apex, sometimes preventing complete chemical debridement of the apical one-third. So new technologies were invented and brought to market — ultrasonic activation of the canal irrigants, which studies showed improvement in the cleaning of the canals; EndoVac (Kerr Endodontics) with negative apical pressure; and the Endoactivator (Dentsply Sirona), a sonically activated device with a flexible polymer tip to aid in acoustic streaming of canal irrigant. Then Photon-Induced Photoacoustic Streaming (PIPS), which is laser-activated irrigation, came onto the endodontic scene and greatly improved the irrigation revolution. Recently, Sonendo® with the GentleWave® multisonic sound-wave technology has brought a buzz of excitement to the endodontic community. The GentleWave procedure optimizes treatment fluids, by removing the unwanted gasses from NaOCL and EDTA and combining the optimized treatment fluids with a proprietary broad range of acoustic energy which leads to cavitation and remarkable clinical results. I have incorporated all of these products clinically and observe first hand the clinical improvement of the endodontic revolution. My friends and family ask me how do you do root canals all day every day? I respond that it’s fun because I am part of the endodontic revolution, and I get to “play” with new toys every day that make me better, more successful, and enhance the patients’ experience. So embrace the endodontic revolution, and borrowing from H&R Block®: “Don’t just get your root canals done; get your root canals won.” Reid V. Pullen, DDS, graduated from USC Dental School in 1999 and then served 3 years in Landstuhl, Germany, in the Army Dental Corps. While serving, he completed a 1-year Advanced Education in General Dentistry. Dr. Pullen moved back to southern California in 2002 and worked as a general dentist in private practice for 2 years before attending the Endodontic Residency at the Long Beach Veterans Hospital. Dr. Pullen graduated from endodontic residency in 2006 and worked in various private practices until opening his own practice in 2007. Dr. Pullen maintains a full-time private endodontic practice in Brea, California. Dr. Pullen became a Diplomate of the American Board of Endodontics in 2013. His hobbies include Jiu Jitsu, golf, surfing, teaching the 2 Day Root Camp Boot Camp, and hanging out with his family.

Endodontic practice 1


Spring 2017 - Volume 10 Number 1


Research/Technology The advantages of instrument compressibility and ProTaper NEXT™ Dr. Michael J. Scianamblo and Mr. Martin Flatland explore some advantageous properties of this file system....................................... 15

Practice profile Michael A. Miyasaki, DDS


Clinical Platelet-rich fibrin in endodontics Dr. Edward S. Lee discusses a tissueengineering material with a variety of applications..................................... 22

Building relationships in endodontics

Clinical research Antibacterial effectiveness of ozone gas and highfrequency electrical pulses over Enterococcus faecalis Drs. Tiago André Fontoura de Melo, Karen Barea de Paula, Francisco Montagner, Alcione Luiz Scur, Liviu Steier, Roberta Kochenborger Scarparo, José Antônio Poli de Figueiredo, and Fabiana Vieira Vier-Pelissera present a study into endodontic disinfection effectiveness .......................................................26

Case study

Financial focus Is your retirement plan tax savvy? Tom Zgainer discusses the impact of taxes on your financial future


Anatomical shaping with XP 3-D Shaper and Finisher Dr. Allen Ali Nasseh discusses nonsurgical retreatment with innovative instruments.....................................30

ON THE COVER Inset X-ray image courtesy of Dr. Alix Davies. See article on page 34.

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Volume 10 Number 1


Genius Files Cross Section Genius Files have double cutting edges with right positive action for asymmetric reciprocation and rotary action

800.552.5512 | © 2017 Ultradent Products, Inc. All Rights Reserved.


Continuing education Risk assessment of endodontic-related nerve injuries: part 2 In the final part of two articles, Dr. Tara Renton explores risk assessment, diagnosis, and management of endodontic-related nerve injuries .......................................................40

Continuing education The benefits and limitations of CBCT


Dr. Alix Davies discusses the use of CBCT in endodontics

AAE preview AAE17 — education, vendors, networking — and all that jazz .......................................................46

Technology Apical negative pressure irrigation advances endodontic treatment Dr. Brett E. Gilbert answers some questions about advances in irrigation .......................................................50

Endodontics and implantology: odd couple or opposites attract? Jordan Reiss examines how implants can fit into the endodontic practice .......................................................52

Practice management Trust — the specialist’s force multiplier Dr. Garth Hatch discusses the benefits of building trust............................... 55

Technology Keep it real with today’s patients........................................56 4 Endodontic practice

Product profile MoraVision™ 3D This operating video microscope system brings a breakthrough to dental technology............................58

PUBLISHER | Lisa Moler Email: MANAGING EDITOR | Mali Schantz-Feld, MA Email: | Tel: (727) 515-5118

Practice development Top five dental marketing scams Cory Roletto, MBA, discusses some marketing tactics to avoid............... 60

Industry news...............61 Small talk Become an essentialist to find happiness in your success Dr. Joel Small identifies how to reach goals while honoring values.............62

Endospective Minimally invasive endodontics: taking root!

ASSISTANT EDITOR | Elizabeth Romanek Email: NATIONAL SALES DIRECTOR | Kristin Sammarco Email: CLIENT SERVICES/SALES SUPPORT | Adrienne Good Email: CREATIVE DIRECTOR/PROD. MGR. | Amanda Culver Email: WEBSITE MANAGER | Anne Watson-Barber Email: E-MEDIA PROJECT COORDINATOR | Michelle Kang Email: FRONT OFFICE MANAGER | Theresa Jones Email: MedMark, LLC 15720 N. Greenway-Hayden Loop #9 Scottsdale, AZ 85260 Tel: (480) 621-8955 Fax: (480) 629-4002 Toll-free: (866) 579-9496 | SUBSCRIPTION RATES 1 year (4 issues) $129 | 3 years (12 issues) $349

Dr. Rich Mounce discusses his guiding philosophy for conserving tooth structure...........................................64 Volume 10 Number 1

The Tip of an Endodontic Revolution The Time for Ultrasonics to Revolutionize Endo Has Come. We are unlocking the full potential of Ultrasonics with a line of masterfully designed tips specifically for endo. Created by world renowned endodontist Dr. Alexandre Capelli, Helsē inserts allow you to perform procedures you never thought possible. Find our complete line of tips and a growing library of minimally invasive procedure guides at

Helsē Ultrasonic The Tip of the Ultrasonic Revolution

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Michael A. Miyasaki, DDS Building relationships in endodontics What can you tell us about your background? I was born and raised in Sacramento, California, and attended dental school at the University of Southern California where I graduated in 1987. During those 30 years, I have been very fortunate to have experienced many different aspects of the dental profession. For 27 of those years, I have been involved in education, mostly in live-patient treatment programs, which I consider the best way to learn. I have had the opportunity to travel and work with my dental colleagues internationally, and I always enjoy seeing that no matter where dentists practice, such as India, Russia, Lebanon, Albania, Mexico, or Australia, they are all very much alike. I have always been an active practitioner, but I returned

to Sacramento 5 years ago to be closer to my family and then purchased a practice 3 years ago. I have also been an editor-inchief of a dental magazine and have been involved at an executive level with many dental companies over the years. Dentistry has been much more and given much more to me than I would have ever thought. I must say, I have loved every day.


Why did you decide to focus on endodontics?

My practice is a general dental practice, and endodontics is one of the services we feel is of value for our patients when we can perform the service in our office. I respect what our endodontic specialist colleagues do and refer when it is in the best interest of our patients or ourselves.

When I graduated dental school, we used hand files and dipped our radiographs. This was an arduous process, and referring the endodontics was often our best option. A few years after I graduated, I took a livedemonstration course given by Dr. Stephen Buchanan. It gave me an appreciation of what I did not know, but he also gave us a system I

Is your practice endodontics?


Dr. Miyasaki at work in his practice 6 Endodontic practice

Volume 10 Number 1


could use that was much more efficient than what I had learned in school. Ever since then, I have tried to learn more to improve my endodontic treatment. We can save our patients so much time if we are preparing a tooth and find that the decay is more extensive than we had planned; and we have the option to provide their endodontic treatment at that time and restore the tooth in a single visit. We know that the success of endodontic procedures is best when the coronal portion of the tooth is sealed quickly. By being able to provide endodontic care, we respect our patients’ precious time and make the entire restorative service more predictable.

How long have you been practicing, and what systems do you use? I have been in practice for 30 years, and over those years have used at least half a dozen systems. Ease of use, versatility, canal navigation, shaping with tooth preservation, retention of tooth structure/ strength, cost, and success are some of the factors that I consider. Today I find that Ultradent’s Genius® system satisfies the factors I consider important. I also find that magnification and cone beam computed tomography, which we use in the office, are great adjuncts to help us diagnose and perform much better endodontics.

Dr. Michael A. Miyasaki with his associate dentists, Drs. Michael Ciccarelli and Myla M. Villanueva

What training have you undertaken? Over the decades, I have taken many endodontic training courses from Dr. Ben Johnson, Dr. Stephen Buchanan, Dr. Cliff Ruddle, Dr. Richard Mounce, and Dr. Kit Weathers. All of them have been excellent educators stressing thorough cleaning and shaping while preserving the radicular tooth structure and then complete obturation. I have found that every course helps me better visualize the root canal systems and treat them.

The team at Miyasaki Dental focuses on the patients’ care and treatment experience

Who has inspired you? I have been very fortunate to have many dental mentors, and to each I am grateful. My family continues to provide me inspiration. My father is a dentist who practiced in the Navy and then for over 50 years in private practice and, over that time, developed deep relationships with his patients. He enjoyed the “work,” and I hope I can work as long. My wife was an assistant for almost 30 years and throughout supported my professional growth. My oldest son runs my office, and to see his growth in business and leadership has been rewarding. And I have a daughter who has just begun her dental Volume 10 Number 1

education at Loma Linda Dental School, and I know she will push me to up my game. My family continues to inspire me, and I feel very fortunate.

What is the most satisfying aspect of your practice? The relationships we have with our patients. Every day I go to work I am with patients who have been in our practice for over 3 to 5 decades. The next most satisfying aspect is the growth we see in our employees and the progressive nature of our practice to help our patients optimize their health and

appearance for decades. The dental profession is very satisfying, but a well-done root canal is always very rewarding.

Professionally, what are you most proud of? Being able to improve other’s lives daily brings me great pride. I see this in the relationships we have developed with our patients, the growth I see in the team that I work with, and the change I see in my colleagues while providing education. I am fortunate to be able to receive so much fulfillment from our profession. Endodontic practice 7


Examples of marketing highlighting our commitment to a lifetime of dental health and three generations of the Miyasaki family involved in dentistry — Dr. Miyasaki with his father and daughter

Top 10 favorites

What do you think is unique about your practice? We are focused on relationships, so after a comprehensive examination, we design treatment plans with the patients’ involvement after we explain the condition of their oral health and the options we have. My job is to show them their condition and the possibilities, and they help me determine what they value most, and we proceed in a way that is comfortable for all.

What has been your biggest challenge? My personal challenge is setting fees that reflect the value of what we provide and yet that work in the world of dental insurance. I was insurance-free for a decade and then purchased a practice that accepted insurance, so we are in the process of transitioning out once again. We want to help our patients and control cost, but we also want time for personal attention and quality, so we can’t compromise. I was recently asked by someone selling a service if I wanted a lower cost product for our PPO patients, and I explained that we don’t treat patients by the fees they pay, but we provide the best we can for everyone. By managing our business carefully, we have been able to strengthen the financial fitness of our practice, allowing us to drop our participation in the last PPO plan I inherited with the practice. We have been 8 Endodontic practice

educating our patients, so they can make the best insurance choices with this change. We have also been modernizing our office with some of the best technology available, such as digital radiography, cone beam computed tomography, bioelectric diagnostic systems for TMJ, CAD/CAM for digital impressions and milling, perioscopy, the Solea® (Convergent Dental) and Gemini® (Ultradent Products, Inc.) lasers, and the Genius endodontic system.

What would you have become if you had not become a dentist? I would have considered a type of ministry. I enjoy serving others and helping others improve themselves. I see ministry as having a unique business model that provides a service but doesn’t require anything in return, and yet people throughout history will die for their beliefs.

What is the future of endodontics and dentistry? Endodontics is so much more today than doing a root canal treatment. Just like when I graduated, a filling was most likely done with amalgam, and today there are many restorative options. With microscopes and reparative materials, we can perform microsurgery to repair and retreat teeth. And in the case of teeth that are not repairable, many endodontists today are assisting the patients to move into implants.

1. My faith gives me both security and humility. It allows me to relax into life. 2. My family. Nothing else matters as much, and they make everything so much more enjoyable. 3. Sirona Galileos ComfortPLUS cone beam computed tomography because it allows us to see so much more from endodontic pathology to implant planning, joint health, and airways. 4. A supportive work team. Like family, we carry each other through the challenges of the day, and we celebrate the successes. We encourage each other to do our best and keep improving. We have fun. 5. Fridays. Our workweek is busy, and a couple days of rest allow us to renew and reconnect to those around us. 6. Nothing. Ever been somewhere where there was nothing? No lights, no sounds, just your thoughts. 7. The Genius® endodontic system, which makes my providing endodontic treatment a pleasant experience. 8. CAD/CAM technology for singlevisit restorative patients. 9. Learning. I deliver hundreds of hours of education every year and take almost as much. I would be disappointed if I didn’t learn something new every day. 10. Our dogs. Always the first to greet me, and they love me unconditionally, or maybe it’s because I feed them. I like to think it’s love.

Volume 10 Number 1

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to craft every Boyd chair to be worthy of all that you stand for. And we honor our promise by using the finest materials, making our chairs affordable, building each one in our own factory in the US, further ensuring its durability with the most rigorous quality control, while giving you the highest level of customization.

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1957 – 2017


Dr. Miyasaki with his 11-year-old pilot son, William

Dentistry overall is becoming more corporate-owned, which I think makes sense, although I think in my career, I would like to maintain ownership of my practice. Today it takes so much more energy and capital to run and grow a practice, and the clinical procedures we do are so much more involved and complex. Our new graduates with their education debt need opportunities to succeed. I am excited about the future, but we all have to be willing to adapt our vision of the dental business model, or I am afraid some will wake one day to find they don’t own much.

What are your top tips for maintaining a successful practice? Keep improving and adapting. The dental profession is changing, but the opportunities are so exciting. Select the right team members focused on serving their patients and train them well to provide the best service possible and allow them to communicate the value of your services to your patients. Embrace change, and invest in education and equipment that will help you provide 10 Endodontic practice

a better end result to your patients. We all have to grow personally and professionally to grow our business. Today consumers are doing their due diligence (which makes them much better healthcare consumers) about their treatment options and outcomes, so we must work hard to stay ahead of them.

What advice would you give to budding endodontists? Find a mentor, and invest in education. Build strong relationships with your referring doctors, and provide them with the education that will make them better diagnosticians as this will make your time with their patients more efficient and productive, but in return you will stand out in the minds of your referring doctors. Again make those around you better. With a mentor, you will continue to grow and increase your value, which will in turn grow your practice; there are very few things that feel as good as that. I am not the same dentist I was 30 years ago for sure, but I don’t even think I am the same dentist I was a week ago with all the constant learning we are doing.

Dr. Miyasaki and family

What are your hobbies, and what do you do in your spare time? There isn’t a lot of spare time, but I have found it important to get some sort of physical exercise daily. Dentistry can take a toll on our bodies, and moving helps the comfort and longevity we will have in our profession. I grew up hunting, fishing, and skiing. Today I try to get out and go fishing with my father, and my youngest son, who is 11 years old, has taken up my hobby of flying small aircraft with me. I always enjoy traveling with family both domestically and internationally, so they have a greater appreciation for what they have. And on weekends, I love getting them all together to enjoy a fine wine, produced locally, with my wife’s food. EP Volume 10 Number 1

WHILE WE CAN’T MAKE THE ROOT CANAL LESS COMPLEX, WE CAN MAKE IT EASIER TO CLEAN Endovac Pure ™ is the only system to leverage the apical negative pressure irrigation technique – a method that is supported by over 200 published studies. With a single handheld controller, you can achieve complete 3D and apical cleaning of the root canal. Endovac Pure ™ removes debris and bacteria from the apical third and provides a continuous flow of irrigants to the canal while minimizing the risk of extrusion past the apex.

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Together, we’re more.


Is your retirement plan tax savvy?

Tom Zgainer discusses the impact of taxes on your financial future


hat’s your retirement plan? Do you have a pension? A 401(k)? Do you think this will be enough for you to live comfortably on? While millions of Americans have a retirement account in place, the scary truth is they have not considered the impact that taxes have on how much of their money they will actually keep. If you haven’t noticed already, our government has some serious spending habits. They’ve racked up not only more than $17.3 trillion in debt, but also $100 trillion in unfunded liabilities with Social Security Tom Zgainer is CEO and founder of America’s Best 401(k) and has helped thousands of companies repair or rescue their retirement plans over the past 15 years. You can learn more at

12 Endodontic practice

and Medicare as well. So what do you think this means for taxes? Will taxes be higher or lower in the future? You have probably been taught to maximize your 401(k) or IRA contributions for tax purposes because each dollar is tax deductible. This, of course, means that you don’t have to pay tax on that dollar today, but instead will defer the tax to a later day. Here is the problem: It’s impossible to know what tax rates will be in the future. So you have no idea how big of a bite taxes will take out of your retirement fund. Most experts will tell you that over time, the only logical direction for taxes to go is up. After all, someone has to pay for those staggering levels of debt the government has accumulated. What does this mean for your retirement plan? In short, it means that what you actually get to keep could be a lot less than you anticipated.

To help you determine which retirement plan is right for you, we help answer some of the most important questions you may have about the impact of taxes on your financial future.

Q: Should you participate in your 401(k) plan? A: The bottom line is that you have to do something. But you have to be smart about it. The 401(k) can be a great piece of tax code that, if structured right, can fuel your retirement for years. But, as we see in most of today’s plans, many 401(k) plans are chock-full of fees and unseen costs. In 2012, service providers became required by law to disclose these fees, but despite this change, the majority of employees still aren’t aware of how much they’re paying — and really, how much they’re losing. Volume 10 Number 1

Up close and personal. ZEISS OPMI Microscopes

ZEISS OPMI® pico and OPMI PROergo® microscopes combine state-of-the-art optics and effortless maneuverability for maximum visualization and optimal comfort. Work ergonomically even at extreme treatment approach angles and view otherwise difficult-to-see regions in greater detail during delicate and complex procedures. For more information, please contact us at 800-442-4020.

Experience ZEISS Visualization at the 2017 Hinman Dental Meeting in Atlanta, Georgia — ZEISS Booth 437. SUR.8485 ©2017 Carl Zeiss Meditec, Inc. All copyrights reserved.

FINANCIAL FOCUS Just be sure to know how your company’s plan stacks up. Go to, and click on “Fee Checker” to assess your company’s plan.

Q: What should you do if you think taxes are going up? A: If you think that taxes will go up in the future, then you may want to consider a Roth retirement plan. A Roth IRA, and more recently the addition of the Roth 401(k), is often overlooked but is actually one of the most tax-efficient solutions to retirement out there. With a Roth account, we pay taxes today, then deposit the after-tax amount, and never have to worry about taxes again. So our money grows tax-free, and we don’t have to worry about taxes when we take our money out. You are completely protected if the government decides to raise taxes in the future. And most importantly, you will know with absolute certainty how much money you will actually have when you decide to start making withdrawals. Most of today’s 401(k) plans allow you “check a box,” and your contributions will

receive the Roth tax treatment. This means you can pay tax today and let your growth and withdrawals steer clear of the tax man. And while a Roth IRA is limited to a $5,500 annual contribution, the Roth 401(k) allows you to deposit $18,000 every year. Just remember, if you decide to check the box and make your 401(k) contributions Roth eligible, you will still be investing in the same list of funds. The only difference will be that you are paying taxes on the income today, while securing your money from taxes in the future.

Q: Is there anything you can do with your traditional IRA? A: Yes, there is. If you think taxes will be going up in the future, then you may want to consider a Roth conversion. With a Roth conversion, the government will allow you to pay the tax on your IRA today (because they could use the money now), and you will never have to pay tax again. Confused? Take John, for example. John has an IRA with $10,000 and is in the 40% tax bracket. This means he would pay $4,000 today and allow the remaining $6,000 to grow and be withdrawn tax-free!

You must learn how to protect your money from unforeseen changes in the environment, particularly taxes.

Some people are automatically turned off from the idea of paying tax today. But remember, you will have to pay taxes eventually. And by doing it now, you are protecting yourself and your nest egg from future tax hikes.

Q: Are there any additional options to save? A: Small business owners or highincome earners who have a steady income and want to reduce their taxes today can find big benefits by coupling a cash-balance plan with their 401(k) plan. A cash-balance, or CB plan, is basically a pension plan that happens to have elements of a 401(k). Like a pension, you won’t be investing any of your own money into the plan. You also don’t have control over the investment choices. But rather than your overall benefits being based on a specific formula that considers how long you’ve worked at the company or what your average salary has been, the CB plan simply takes a set percentage of your salary each year, plus a set interest rate, and adds it into your account. The best part is that you can max out your 401(k) plan and a profit-sharing plan and then still add a CB plan to create some substantial — and fully deductible — contributions. A cash-balance plan starts to get very exciting when you get older, as you can put a more substantial amount of money away while reducing your tax liability. A cash-balance plan essentially allows you to squeeze 20 years of savings into 10 years. Remember, it’s not enough to just protect your nest egg from the unscrupulous fees and costs that some 401(k) plans impose; you must learn how to protect your money from unforeseen changes in the environment, particularly taxes. Whether this means selecting a plan in which you pay your taxes today, or one that allows you to defer your taxes until later, you must find a way to optimize your growth and be fully aware of how much you will get to keep. Don’t be blindsided by the hit the tax man will take on your nest egg. Protect your nest egg, and protect your road to retirement because by doing so, you are ultimately protecting your financial future. EP

Is your plan tax savvy? Find out here: 14 Endodontic practice

Volume 10 Number 1

Dr. Michael J. Scianamblo and Mr. Martin Flatland explore some advantageous properties of this file system Abstract Introduction This study investigates the unique properties ProTaper NEXT™, a file that displays an offset cross-sectional center of mass and its concomitant compressibility. Methods Specific tests using custom-designed fixtures were developed to measure the XFile compressibility in comparison to a traditional design ProTaper Universal or F-Files. The files were compressed by applying a force to the test file perpendicular to the axis of rotation. The compression or movement of the file due to the applied load was measured, and the X-Files were compared with the standard F-File. Results The X-Files exhibited a range of elastic compressibility as a result of an applied load. This compressible range was seen when the applied load was between 1 N and 10 N. The amount of compression of the X-File Michael J. Scianamblo, DDS, is an endodontist and the developer of Critical Path Technology. He is a postgraduate and fellow of the Harvard School of Dental Medicine and has served as a faculty member of the University of the Pacific and the University of California Schools of Dentistry in San Francisco. He has also served as president of the Marin County Dental Society, the Northern California Academy of Endodontists, and the California State Association of Endodontists. He has presented numerous lectures nationally and internationally, and is a recognized author in endodontics, dental materials, and instrumentation. He maintained a private practice in endodontics in San Francisco and Marin County, California, since 1978. His career is currently dedicated to instrument development, and he has been awarded 11 U.S. patents and two international patents with several patents pending. Martin L. Flatland, BSME, has more than 20 years of experience in biomedical engineering and new product development and is the CTO and Chief Engineer of SiteSelect Medical Technologies. Dr. Flatland has also worked in R&D for both Richard Allan Medical and Imagyn Medical Technologies and began his engineering career at Stryker Medical, where he worked on the product team that developed the first electrically controlled patient handling unit. Dr. Flatland holds 16 U.S. patents and is listed as the primary inventor on four pending U.S. patent applications. He holds a BSME and has completed graduate work in mechanical engineering at Western Michigan University. He has maintained memberships in Tau Beta Pi Engineering Honor Society and the American Society of Mechanical Engineers.

Volume 10 Number 1

Figure 1: Depicts a transverse wave, which consists of oscillations occurring perpendicular or at right angles to the direction of the wave. The waves are composed of crests and troughs with a specific amplitude that determines the energy or force transmitted by each wave

(deflection) in this low-force range was between .05 mm and .15 mm, depending upon the diameter of the file cross section that was tested. The traditional endodontic file required a larger applied force, typically greater than 25 N, to show any significant deformation. Conclusions The X-Files exhibit substantial elastic compressibility of between 0.05 mm to 0.15 mm compared to traditional F-Files, where the compressibility was found to be negligible. The amount of compression is dependent upon file curvature and the crosssectional area of file under observation. This compressibility feature can lend itself to cut and remove material more efficiently and more safely.

Introduction Traditional endodontic instrument designs have a center of rotation and a center of mass that are identical, dictating a linear trajectory or path of motion. These designs, of course, facilitate elastic memory and the restoration of the original file shape. The use of nickel-titanium in the manufacture of endodontic files further facilitates this function. This has been thought to be of paramount importance during root canal preparation, whereby the restoring force can be pitted against the balancing force as described by Roane, et al. (1985) and Southard, et al., (1986). However, the work of Peters (2001) has indicated that it is this precise function that prevents the

instruments from contacting the root canal walls, leaving as much as 35% of the internal anatomy of the canal untouched and the preparation poorly centered. In addition, the work of Sattapan, et al. (2000), Spanaki-Voredi, et al. (2006), Kramkowski and Bachall (2009), and others indicates that instrument binding and cyclic fatigue with subsequent instrument failure remains a common problem with nickeltitanium instruments. An alternative approach to traditional instruments designed with a coincident center of rotation and center of mass are instruments that have an “offset” crosssectional center of mass from the center or axis of rotation. These instruments have been described as swaggering files but are more accurately defined as instruments that cut on a precessional axis or via a cyclical wave and are currently marketed under the trade name ProTaper NEXT. Precession describes the motion that occurs whenever the axis about a body, which is spinning, is itself rotating about another axis. When the center of mass of the crosssectional area of a file is offset, the cutting motion is no longer linear in mechanical terms, but helical or cyclical. Swagger, or in more sophisticated terms, precession, is viewed as a mechanical wave that travels along the length of the file. As with any wave traveling through a medium, a crest is seen moving from point to point. This crest is followed by a trough, which in turn, is followed by the next crest. The wave pattern that is generated by ProTaper NEXT is a transverse wave pattern. Endodontic practice 15


The advantages of instrument compressibility and ProTaper NEXT™

RESEARCH/TECHNOLOGY Transverse waves oscillate perpendicular to the direction of propagation. For example, if you anchor one end of a rope and hold the other end in your hand, you can create transverse waves by moving your hand up and down (on the z-axis). Notice, however, that you can also create waves by moving your hand side-to-side (on the y-axis). ProTaper NEXT is configured to oscillate or spiral in both the y-axis and the z-axis, while the wave propagates along the x-axis. This cyclical wave pattern or precessional cutting axis is inscribed in the design of ProTaper NEXT by offsetting a rectilinear cross section (Figure 2), which revolves

around the central axis as shown in the SEM in Figure 3 (courtesy of Dr. Sergio Kutler) and the “wire perspective” in Figure 4 below. The performance of such a design is difficult to describe in two-dimensions. Thus, the reader is referred to a video provided by the following link: watch?v=dNHzySw51Uk. The SEM and the wire perspective shown can lend to the visualization of “compressibility” of these files. Previous to ProTaper NEXT, Hof, et al. (2010); Metzer, et al. (2010); and Peters and Paque (2011) described an ultrasonic instrument called the Self-Adjusting File,

Figure 2: A schematic of offset rectilinear cross section of ProTaper NEXT. As can be seen from this figure, only two cutting angles engage the walls of the root canal at any one time. This offset rectilinear cross section not only contributes to the innate flexibility of the file, but also permits intermittent cutting, which mitigates cyclic fatigue. The large clearance angle opposite the cutting flutes facilitates hauling and elimination of debris

Figures 3-4: An SEM of the profile and an Auto-CAD image of the X-File demonstrating the spring or coil-like profile of the instrument

Figure 5: A schematic of the profile and dual axis of Protaper NEXT. Axis 1 is the central or rotational axis, and Axis 2 is the cutting or precessional axis. The distance-X between the two axes decrease continuously from shank to tip, where the axes meet, leaving the tip completely centered. The offset center of mass, inherent in this design, enables the X-File to cut precessionally 16 Endodontic practice

which displayed a compressible lattice with the capability of adapting itself to the canal shape, improving centering and reducing the amount of unprepared tooth structure. Ruckman, et al. (2013) demonstrated that the Self-Adjusting File was significantly better than hand instrumentation in cleaning long-oval-shaped canals at mid-root. Until now, there have been no reports of rotary instruments, which feature the property of compressibility. The following discussion describes such an instrument.

Description As previously mentioned, ProTaper NEXT represent a new concept in endodontic file design, in which the center of mass of the cross-sectional area is offset from the center of rotation. The axis of rotation or central axis of the X-File, which defines the theoretical center of rotation, is shown by Axis 1. Axis 2 follows the geometric center of the X-File. The amount of offset between the center of rotation and the center of mass is defined by the distance between these two axes and varies along the length of the file and shown as the distance-x (Figure 5). During instrumentation of the root canal, typically at 300 rpm to 350 rpm and 2 Ncm to 4 Ncm, the geometric axis or Axis 2 shown in Figure 5, becomes a precessional axis. As mentioned previously, when the X-File is rotated, it produces a transverse mechanical wave defined by a series of peaks and troughs. The amplitude or heights of the peaks are at a maximum when the file is in its free and unconstrained position. When the file is inserted into the root canal, the peaks will be compressed. The amount of compression will depend upon the diameter and the curvature of the canal. Theoretically, when the file is fully compressed, Axis 2 will flatten out and be collinear with Axis 1. As each peak along the file is elastically compressed, it behaves like a small spring and is a source of potential or stored energy.

Analysis of the file as a variable rate spring Another factor that must be considered in understanding the function of the X-File is the file stiffness and/or flexibility. The X-File possesses the unique property of a coil or spring, which differentiates it from the traditional endodontic files. Stiffness and/ or flexibility is often referred to as a spring constant, which is defined as the amount of force that is required to cause a unit of deformation. In its general form, k = F / δ, where k equals the stiffness, F equals force, and δ equals displacement. Equations for the determination of the spring constant of actual Volume 10 Number 1

Volume 10 Number 1

Figure 6: Demonstrates the localized section of the file as it is bent to conform to the cavity during use. L is the distance between the crest of two nodes, with which we can analyze the spring rate of a single wave between the crests

Figure 7: A schematic of a simply supported beam and the equation used to determine the stiffness or restoring force of the simply supported beam (where x is the maximum reflection)

Figures 8-9: Demonstrates the instrument in its constrained or compressed condition. When the file is fully constrained, x (as shown in Figure 5), which represents the deflection of the file due to F, would initially be zero or nearly zero. Demonstrates the file’s tendency will be to return to the natural or uncompressed state in which it is precessing about its central axis

Figures 10A -10C: Scanning electron micrograph of the instrument itself demonstrating the nodes of the file and the instrument in the unconstrained or uncompressed condition

Figure 9, the spring force or cutting force will be nearly zero, and the file will be rotating freely about the central axis. A design of this nature would theoretically allow the instrument to engage the intaglio of the root canal space intermittently as the constrained coil is inserted in the canal and allowed to unwind, releasing a theoretical amount of stored energy. The release of stored energy is dissipated gradually, which minimizes binding, which would mitigate cyclic fatigue, while providing the opportunity

to clean both inner and outer curvature of the canal wall more thoroughly. This mitigation of cyclic fatigue has been verified by Pérez-Higueras, et al. (2014); Nguyen, et al. (2014); and Elgnaghy, et al (2014). These finding are particularly impressive considering that the cross-sectional area of X-Files is approximately 30% narrower in the y-axis and 40% narrower in the z-axis when compared to the F-Files (Scianamblo, 2016). In addition to the mitigation of cyclic fatigue, Zhao, et al. (2014), who Endodontic practice 17


mechanical systems are widely available in engineering literature. Due to the constantly changing cross section of the X-File, the spring constant of the file will vary along its length. This spring constant, together with the file precession, directly affects the cutting forces applied to the surrounding root dentin during application. In one respect, we can look at a localized section of the file as it is bent to conform to the canal shape during use, shown as L in Figure 6. If we define the localized section of the file to be analyzed using the terminology defined in the waveform discussion earlier, we can analyze the spring rate of a single wave crest between two nodes. In this application, the stiffness can be analyzed using the equations for a simply supported beam in Figure 7. L represents the distance between any two nodes; I represents the moment of inertia, which is dependent upon the crosssectional area of the file and will vary along its length; and E represents the modulus of elasticity (Young’s Modulus), which is used to define the stiffness of different materials. We define the variables presented in Figures 6 and 7 with respect to the X-File as follows: • L would represent the distance between any two nodes. • I represents the moment of inertia, which is dependent upon the crosssectional area of the file and will vary along its length. • E represents the modulus of elasticity (Young’s Modulus), which is used to define the stiffness of different materials. When we evaluate the initial conditions of the X-File as it is inserted into a root canal, we look at the reverse of what is depicted in Figure 7 above and shown in Figure 8. The instrument shown in Figure 8 is in its constrained or compressed condition. Here F represents the force exerted on the file by the canal wall. Since the X-File is built with multiple nodes and potential deflections, the tendency of F will be to straighten out the file along its length. When the file is fully constrained, x, which represents the deflection of the file due to F, would initially be zero (or nearly zero). As the file begins to rotate, its tendency will be to return to the natural state in which it is precessing about its central axis. As it attempts to precess, the cutting edges, under the load of the spring force, will begin to remove material from the surrounding cavity. This process will continue until the file has enlarged the canal based the file diameter and the precession axis. In this final unconstrained condition, shown in


Figures 11A-11D: A. Illustrates a custom fixture used to measure the force applied perpendicular to the central axis (Figure 5, Axis 1) of the file. This testing was performed to measure the compressibility over the full length of the file. B. Illustrates the custom fixture used to measures the compression at individual peaks along the length of the file. The test setup is similar to that used for the full length testing. C-D. Equipment used for testing included an Instron Model 4442 Tension/Compression Tester, a DAQ (Data Acquisition System), custom fixturing to position the files for testing, a Toolmakers microscope, a stereo microscope, and miscellaneous measuring equipment, including a, micrometer, calipers, and gage pins

demonstrated that during the preparation of curved canals, PTN had less apical transportation than the canals prepared using WaveOne® or ProTaper® Universal, Arias, et al. (2014) found that instruments in ProTaper Next set showed greater regularity in peak torque for small and large canals than ProTaper Universal instruments, which implies an accommodation of the file under power. Clinicians have also noted the ease with which ProTaper NEXT can negotiate complex anatomy, particularly severely curved canals and complex bends. These attributes have lent to the speculation that ProTaper NEXT is compressible, which lends to the following study.

Objective The objective of this study was to analyze the compressibility of the X-File compared to traditional designs and test the influence of the compressive forces on the ability of the X-File to cut material.

Methods and materials The tests used to investigate the compressibility of these instruments were specially designed. The endodontic files used included the ProTaper NEXT (X-File) and the ProTaper Universal (F-File). Both file types are constructed of nickel-titanium and manufactured by Dentsply Maillefer (Switzerland) or Dentsply International. All files tested were 25 mm long. Equipment used for testing included an Instron Model 4442 Tension/ Compression Tester, a DAQ (Data Acquisition System), custom fixturing to position the files for testing, a Toolmakers microscope, a stereo microscope, and miscellaneous measuring equipment, including a, micrometer, calipers, and gage pins.

Compression testing: full file length The compressibility testing performed here measures the amount of file compression when a force is applied perpendicular to the central axis (Figure 5, Axis 1) of the file. 18 Endodontic practice

Figure 12: Shows a data plot comparison from the compression testing of the X4-File verses the F4-File. This plot is representative of the data plots of all of the files sizes tested. The response of the X-File to the applied load is clearly different from that of the F-File. For analysis purposes, the plot is divided into three zones as labeled in Figure 12

This testing was performed to measure the compressibility over the full length of the file. To perform the test, each file was inserted into a custom-testing fixture (Figure 11A). A microscope was used to locate the file in a pre-defined test position, and the file was then locked into this position. With the file locked in position, a compressive force was then applied along the length of the file using the full length applicator. The applied load and corresponding compression for each file tested was captured using a data acquisition system. Two sets of the X-Files and two sets of F-Files were tested. Each set included five files: for ProTaper NEXT sizes 17/04, 25/06, 30/07, 40/06, and 50/06 and for ProTaper Universal sizes 20/07, 25/08, 30/09, 40/06, and 50/05.

Compression testing: localized In an effort to more clearly define the file compression that is exhibited by the X- Files, this test measures the compression at individual peaks along the length of the file. The test set up is similar to that used for the full length testing. A localized force applicator is now used to apply the compressive force at specific points along the length of the

file (Figure 6). ProTaper NEXT X-4 File (tip size 40) was used for this testing. ProTaper Universal or the standard file design does not exhibit any localized peaks or valleys, and therefore, this test is not applicable.

Results Compression testing: full file length There is a measurable difference in the compressive behavior of the X-File and the F-File. This difference was consistent on all files tested. Figure 12 shows a data plot comparison from the compression testing of the X4 and F4 Files. This plot is representative of the data plots of all of the files sizes tested. The response of the X-File to the applied load is clearly different than that of the F-File. For analysis purposes, the plot is divided into three zones as labeled in Figure 12. Table 1 compares the file compression in the compression zone for all files tested. Compression testing: localized Localized compression testing was performed at four points along the length of the X-4 file, as represented in Figure 13. The distance of each point measured from the tip of the file is given in Table 2. The data Volume 10 Number 1

Table 1: Comparison of the full length file compression in the compression zone File type and size File compression (mm) at 10N





















We see from the table that the X1 and the X2 files were the most compressible with a compressibility of 0.114 mm and 0.22 mm, the equivalent of two instruments sizes in the ISO system of file sizes

Figure 13: Localized compression testing was performed at four points along the length of the X-File as shown Table 2: Measurements of the force and the distance as the file was compressed Test position

Distance from tip (mm)

Spring rate: k = δF / δx (N/mm)

Available work: W = ∆E = 1/2 k(δ22-δ12)

















From these measurements we were able to determine the Spring Rate (k). As the file rotates, this force is available to perform work (work = Force x distance). The amount of work available is shown in column 4 above. This work is available to cut and increase the cavity size without any (or nearly any) down force required

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Endodontic practice 19


from each test point was plotted and used to analyze the spring-like behavior for each wave of the file. During the compression testing of the files, we were able to measure both the force and the distance as the file was compressed along different points along its length. From these measurements, we were able to determine the Spring Rate (k). When the file is inserted into the cavity, it may be compressed. The amount of compression will depend upon the size of the cavity. When the file is a maximum compression, each wave exerts a force on the cavity wall. The size of the force based upon the spring rate is shown in the table. As the file rotates, this force is available to perform work (work = Force x distance). The amount of work available is shown in column 4 above. This work is available to cut and increase the cavity size without any (or nearly any) down force required. This is of particular importance, since the X-Files are one of the few files systems that do not require significant forcible apical pressure or a down force to engage them. This, of course, implies a lower operating torque and lends to the safety of the files.


Figure 14: Postoperative radiograph of a lower first molar with three separate canals. The mesial canals were prepared with files X1 and X2 to the apex using X3 and X4 in the upper two-thirds of the canals in a back-stepping modality. The distal canal was prepared with X1, X2, and X3 to the apex using the X4 and X5 in the upper two-thirds of the canals in a back-stepping modality. The canals were obturated using Schilder technique (Courtesy of Dr. Darron Rishwain, San Rafael, California)

Figure 15: A postoperative radiograph of an upper first molar with severely dilacerated mesiobuccal canals. The mesiobuccal canals were prepared with files X1 and X2 only. The palatal and distobuccal canals were prepared with X1, X2, and X3. The canals were obturated using Schilder technique (Courtesy of Xenia Brant, Belo Horizonte, Brazil)

Figure 16: Postoperative radiograph of an upper second bicuspid with two canals. The canals were prepared with files X1 and X2 prototypes in the apical half. The coronal half was enlarged with the X3 and X4 in a step-back modality. The canals were obturated using Schilder technique or warm gutta percha (Dr. Michael Scianamblo, San Rafael, California)

Discussion ProTaper NEXT or the X-Flies demonstrate an elastic compression that is not present in the files designed with a traditional cross-sectional area that is centered such as ProTaper Universal. This compressibility is a result of the unique waveform design of the X-Files or ProTaper NEXT. Compressibility was observed in all of the X-Files tested, with the amount of compression being dependent upon file cross section and wave height. The difference in the behavior of the two file types is clearly shown in Figure 12. This graph is best analyzed by defining three sections:Â 1. Start Zone, 2. Compression Zone, and 3. File Deformation Zone. The start zone is represented by the flat line that starts each data set. The start zone is apparent in all files tested. The start zone represents the initial bending of the file as the force applicator bends the file downward until contact is made with the fixed anvil underneath the file. The applied force associated with the start zone ranges from 0.5 N to 1.1 N, depending upon the file under test. The resulting deflection range associated with the start zone is from zero to 0.13 mm. The start zone represents the force required to initially deflect each file along its length. The compression zone is only apparent in X-File test data and clearly differentiates the compressive behavior of the X-File from the standard F-File. The compression zone represents the compression of the waveforms that are unique to the X-File. Depending upon the file under test, the compression range is seen typically between 1N and 10N applied force. In all files tested, the data shows that the X-Files typically compress between 0.13 mm and 20 Endodontic practice

Figure 17: A postoperative radiograph of a lower third molar with severely dilacerated canals. The mesial and distal canals were prepared with files X1 and X2 only. The canals were obturated with ThermofilÂŽ (Courtesy of Dr. Giuseppe Cantatore, Milano, Italy)

0.20 mm in this force range. In comparison, the standard F-file typically compressed between 0.05 mm and 0.08 mm in this force range, which is negligible.

Clinical ramifications and benefits Taken in the context of instrument design and file diameters, upon full compression and deformation, a change from 0.10 mm to 0.20 mm is a net change of approximately 0.10 mm, which is the equivalent of two instrument sizes in the ISO file size system. For example, if the net compressibility of the X1 is 0.114 mm as shown in Table 1, the X1 (which is 17/04 at the tip) has a diameter of 0.24 mm at D3 (equivalent to a 25K file, but is convertible to a 0.14 when full compressed (equivalent to a 15k file). The accommodation or translation of the file from a larger diameter to a smaller diameter would necessarily affect a number of clinical outcomes. As mentioned previously, ProTaper NEXT has been shown to have greater resistance to cyclic fatigue. The characteristic of compressibility, however, should also allow the file to remain well centered, and transitioning from one file to the next should be easier — i.e., more regularity in peak torque. As mentioned, research done by Zhao, et al.,

demonstrated that during the preparation of curved canals, PTN had less apical transportation than the canals prepared using WaveOne or ProTaper Universal. And Arias, et al., found that instruments in ProTaper Next set showed greater regularity in peak torque for small and large canals than ProTaper Universal instruments, which implies that the instruments transition easily from one instrument to the next. These benefits are manifest clinically, by the ability of the operator to negotiate severely curved, tortuous, and long canals without over enlarging the upper part of the canals as shown in Figures 14-17 above. A clinical observation that has been reported by many clinicians using ProTaper NEXT is that the instruments must be used several times before the next largest file is introduced, for example, advancing from the X1 to the X2. This observation is due, again, to the compressibility of the file and the fact that that instruments are still constrained after the first introduction. Once the instrument is no longer constrained, advancement to the next largest file is forthcoming. Tests are currently being developed to investigate other potential benefits; for example, cleanliness and interruption of the smear layer. Volume 10 Number 1

The X-Files exhibit elastic compression due to an applied side load that differentiates them from traditional file designs. Compression of the X-File results in a store of potential (spring) energy, which allows the instrument to continue to expand as it rotates under power and to cut with little or no down force. When the file is rotated, the spring energy is converted to work done per unit time, which is effectively used to cut and remove material more efficiently, while lending safety to the system. EP REFERENCES 1. Arias A, Singh R, Peters OA. Torque and force induced by ProTaper Universal and ProTaper Next during shaping of large and small root canals in extracted teeth. J Endod. 2014;40(7):973–976. 2. Elnaghy, AM, Elsaka, SE. Assessment of the mechanical properties of ProTaper Next nickel-titanium rotary files. J Endod. 2014;40(11):1830–1834. 3. Hof R, Perevalov V, Eltanani M, Zary R, Metzger Z. The selfadjusting file (SAF). part 2: mechanical analysis. J Endod. 2010;36(4):691–696. 4. Kramkowski TR, Bahcall J. An in vitro comparison of torsional stress and cyclic fatigue resistance of ProFile GT and ProFile GT Series X rotary nickel-titanium files. J Endod. 2009;35(3):404–407.



5. Metzger Z, Teperovich E, Zary R, Cohen R, Hof R. The self-adjusting file (SAF). part 1: respecting the root canal anatomy — a new concept of endodontic files and its implementation. J Endod. 2010;36(4):679–690. 6. Metzger Z, Teperovich E, Cohen R, Zary R, Paqué F, Hülsmann M. The self-adjusting file (SAF): part 3: removal of debris and smear layer — a scanning electron microscope study. J Endod. 2010;36(4):697–702. 7. Nguyen HH, Fong H. Paranjpe A, Flake NM, Johnson JD, Peters OA. Evaluation of the resistance to cyclic fatigue among ProTaper Next, ProTaper Universal, and Vortex Blue rotary instruments. J Endod. 2014; 40(8):1190–1193. 8. Pérez-Higueras JJ, Arias A, de la Macorra JC, Peters OA. Differences in cyclic fatigue resistance between ProTaper Next and ProTaper Universal instruments at different levels. J Endod. 2014;40(9):1477–1481. 9. Peters OA, Paqué F. Root canal preparation of maxillary molars with the self-adjusting file: a micro-computed tomography study. J Endod. 2011;37(1):53–57. 10. Peters, OA, Schӧnenberger K, Laib A. Effects of four Ni-Ti preparation techniques on root canal geometry assessed by micro computed tomography. Int Endo J. 2001;34(3):221-230 11. Roane JB, Sabala CL, Duncanson MG Jr. The “balanced force” concept for instrumentation of curved canals. J Endod. 1985;11(5):203-211. 12. Ruckman JE, Whitten B, Sedgley CM, Svec T. Comparison of the self-adjusting file with rotary and hand instrumentation in long-oval-shaped root canals. J Endod. 2013;39(1):92-95. 13. Sattapan B, Nervo GJ, Palamara JE, Messer HH. Defects in rotary nickel-titanium files after clinical use. J Endod. 2000;26(3):161-165. 14. Scianamblo MJ. Critical path endodontic instruments for preparing endodontic cavity spaces. U.S. Patent No. 6,942,484, Sept. 13, 2005 15. Scianamblo MJ. Critical path endodontic instruments for preparing endodontic cavity spaces. U.S. Patent No. 20060228669 Oct. 2006. 16. Scianamblo MJ. Bending endodontic instruments. EPO Patent No. 1,709,934 B1 Apr. 2006. 17. Scianamblo MJ. Endodontic instruments for preparing endodontic cavity spaces. U.S. Patent No. 7,955,078, June 2011. 18. Sianamblo MJ. The envelope of motion and ProTaper NEXT™. Endodontic Practice US. 2016;9(2):13-16. 19. Spanaki-Voreadi AP, Kerezoudis NP, Zinelis S. Failure mechanism of ProTaper Ni-Ti rotary instruments during clinical use: fractographic analysis. Int Endod J. 2006;39(3):171-178. 20. Southard DW, Oswald RI, and Natkin E. Instrumentation of curved molar root canals with the Roane technique. J Endod. 1987;13(10):479-489. 21. Zhao D, Shen Y, Peng B, Haapasalo M. Root canal preparation of mandibular molars with 3 nickel-titanium rotary instruments: a micro-computed tomographic study. J Endod. 2014;40(11):1860-1864.

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Endodontic practice 21


Platelet-rich fibrin in endodontics Dr. Edward S. Lee discusses a tissue-engineering material with a variety of applications Introduction Platelet-rich fibrin (PRF) is a bioactive material made from the centrifugation of a patient’s whole blood. It is a second-generation platelet concentrate first described by Choukroun1 and is used to accelerate soft and hard tissue healing. This simplified and cost-effective chairside procedure results in a resorbable fibrin matrix enriched with platelets and leukocytes. PRF provides a rich source of growth factors, including plateletderived growth factors (PDGFs), transforming growth factors (TGFs), vascular endothelial growth factor (VEGF), and insulin-like growth factor (IGF).2 The growth factors are slowly released during the course of the healing process.3 Because of the unique character of PRF, it is used as a tissue-engineering material with a wide range of dental applications.4,5 PRF is currently recommended as a scaffold material for regenerative endodontics.6 The following is a case study for its application in endodontics. Benefits and other applications are also discussed.

Case study A 67-year-old female patient presented with mild discomfort and swelling around tooth No. 14. Her medical history was noncontributory. Teeth Nos. 12, 13, and 15 had been extracted more than 15 years previously and the area restored with a fixed bridge from teeth Nos. 11 to No. 14. The radiograph revealed lateral bone loss around the mesial buccal root with a 9 mm periodontal probing with probing WNL on other sites around the tooth. The patient was informed that she had a vertically fractured mesial buccal root (Figure 1). Treatment options were discussed, including extraction and replacement with implants or a removable partial denture. The patient decided to do a mesial buccal root amputation procedure and save the existing tooth and the bridge. Dr. Edward S. Lee has a private practice in San Francisco, California. He is an innovator in endodontics and is the inventor of the MTA Pellet Forming Block. To learn more about PRF, visit Disclosure: Dr. Lee has no commercial interest in any of the products or companies mentioned in this article.

22 Endodontic practice

Figure 1: Preoperative radiograph showing bone loss around the mesial buccal root

Venous blood was drawn from the patient’s median cubital vein and collected in three 10 ml BD Vacutainer® (BD Worldwide) tubes without anticoagulants. The blood was immediately centrifuged at 1500 RPM for 10 minutes (MyRGF-I centrifuge, Boca Dental Supply, LLC). Three layers form in the tube: 1. The lower fraction contains the RBCs. 2. The middle fraction contains the PRF clot. 3. The upper fraction contains the acellular platelet poor plasma (PPP) (Figure 2). The middle portion containing the PRF clot was cut and removed from the RBC layer (Figure 3). The PRF clot was compressed to form a membrane using a membrane processing box (PRF MyRGF Box, Boca Dental Supply, LLC) (Figures 4, 5, 6). The liquid from the compressed membrane was collected and mixed with allograft bone (BoneBank Allograft, San Antonio, Texas). The collected liquid contains fibrin, which acts as a binder for the allograft bone that will be utilized and helps prevent graft migration from the intended site. A full thickness trapezoidal flap with vertical releasing incisions mesial to No. 13 and distal to No. 14 was made. Upon reflection of the flap, a bone dehiscence over the mesial buccal root and a vertical root fracture were confirmed. A Lindemann bur was used to section the mesial buccal root at a supracrestal level, and a standard Class 1 root-end preparation was completed

Figure 2: Whole blood after centrifugation demonstrating the separated layers

Figure 3: Separation of the PRF clot from the red blood cell layer

using ultrasonic instrumentation (ProUltra® Surgical Endo Tip, Dentsply Tulsa). The root was filled using a dentin bonding agent (Futurabond®, Voco Dental ), a flowable composite (Virtuoso® Flowable, Denmat), and polished with rubber points (Figure 7). The allograft bone mixture was placed into the bony defect followed by coverage with PRF membranes (Figures 8 and 9). Figure 10 shows the immediate postoperative Volume 10 Number 1


Figure 4: PRF prior to pressing in the processing box

Figure 5: PRF pressed into membranes

Figure 6: PRF ready to be delivered

Because of the unique character of PRF, it is used as a tissue-engineering material with a wide range of dental applications. Figures 7-8: 7. Mesial buccal root resected and filled with composite. 8. Allograft bone mixed with PRF liquid. The PRF liquid is a fibrin adhesive binder and prevents the graft material from migrating

radiograph. The sutures were removed after 1 week with minimal to no pain reported by the patient after the procedure. Figure 11 shows the 1-month healing. The area is healing with very little recession around the root amputation site. Figures 12 and 13 show the area after 7 months of healing. The bone has filled in, and the gingival architecture is excellent with no inflammation.

Discussion Platelets play a crucial role not only in hemostasis but also in the wound-healing process.7 Growth factors contained within the α-granules of the platelets help regulate hard and soft tissue repair. These growth factors include platelet-derived growth factors (PDGFs), transforming growth factors (TGFs), vascular endothelial growth factor (VEGF), and insulin-like growth factor (IGF). Leukocytes found in PRF also release growth factors, including TGFβ-1 and VEGF.3 The growth factors help promote cell migration, attachment, differentiation, and proliferation.2 Leukocytes cytokines, such as IL-1, IL-4, IL-6, and TNF-α, are also contained within PRF and help with immune and inflammatory regulation.8 PRF produces a significantly higher concentration of platelets and fibrin when compared to the initial input of whole blood volume.9 Growth factors within PRF are slowly and continuously released during healing.3 A key feature of the PRF process is the slow polymerization of fibrinogen into fibrin Volume 10 Number 1

Endodontic practice 23


Figure 9: Several pieces of PRF membranes are layered over the allograft bone mixture

Figure 11: 1-month postoperative healing. There is minimal recession around the amputated mesial buccal root area

during centrifugation. A fine and flexible fibrin network forms resulting in an architecture that is characterized as a less rigid framework.10 PRF is a flexible, elastic, and resilient biomaterial able to support cytokines enmeshment and cellular migration.11 The high tear elastic modulus of PRF makes it suturable and functions much like a fibrin bandage.12 This helps promote wound closure and mucosal healing. The compressed PRF liquid contains growth factors13 and proteins such as vitronectin and fibronectin.2 The PRF liquid can be mixed with allograft bone to help improve the handling characteristics of the graft and prevent graft migration during the healing process. PRF is a more simplified technique compared with platelet rich plasma (PRP). PRP is a first-generation platelet-concentrate technique involving the use of anticoagulants, multiple centrifugation cycles, and surgical additives.14 The low-density fibrin 24 Endodontic practice

Figure 10: Immediate postoperative radiograph demonstrating resection of the affected root, retrofill of the orifice, and grafting of the osseous defect

Figure 12: Radiograph at 7-month recall demonstrating good bone-fill at the resected and grafted mesial buccal root area

Figure 13: 7-month recall shows good gingival architecture. The tissues have filled in, and there is no recession around the amputated root. Full gingival contours minimize food impaction and help with daily home care Volume 10 Number 1

6. American Association of Endodontists. AAE Clinical Considerations for Regenerative Procedure. Revised 4-1215. research/research/currentregenerativeendodonticconsiderations.pdf. Accessed January 19, 2017. 7. Laurens N, Koolwijk P, de Maat MP. Fibrin structure and wound healing. J Thromb Haemost. 2006 May;4(5):932-939. 8. Dohan DM, Choukroun J, Diss A, Dohan SL, Dohan AJ, Mouhyi J, Gogly B. Platelet-rich fibrin (PRF): a second-generation platelet concentrate. Part III: leukocyte activation: a new feature for platelet concentrates? Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2006 Mar;101(3):e51-e5. 9. Lucarelli E, Beretta R, Dozza B, Tazzari PL, O’Connel SM, Ricci F, Pierini M, Squarzoni S, Pagliaro PP, Oprita EI, Donati D. A recently developed bifacial platelet-rich fibrin matrix. Eur Cell Mater. 2010;20:13–23. 10. Mosesson MW, Siebenlist KR, Meh DA. The structure and biological features of fibrinogen and fibrin. Annals of the New York Academy of Sciences. 2001;936:11–30. 11. Dohan DM, Choukroun J, Diss A, Dohan SL, Dohan AJ, Mouhyi J, Gogly B. Platelet-rich fibrin (PRF): A secondgeneration platelet concentrate. Part I: technological concepts and evolution. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2006;101(3):e37–e44. 12. Khorshidi H, Raoofi S, Bagheri R, Banihashemi H. Comparison of the Mechanical Properties of Early Leukocyte- and Platelet-Rich Fibrin versus PRGF/Endoret Membranes. International Journal of Dentistry. Vol. 2016, Article ID 1849207, 7 pages, 2016. doi:10.1155/2016/1849207. 13. Su CY, Kuo YP, Tseng YH, Su CH, Burnouf T. In vitro release of growth factors from platelet-rich fibrin (PRF): a proposal to optimize the clinical applications of PRF. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2009 Jul;108(1):56-61. 14. Marx RE, Carlson ER, Eichstaedt RM, Schimmele SR,

Strauss JE, Georgeff KR. Platelet-rich plasma: growth factor enhancement for bone grafts. Oral Surg Oral Med Oral Pathol, Oral Radiol, Endod.1998;85(6): 638–646. 15. Minsk SL, Polson AM. The role of root resection in the age of dental implants. Compend Contin Educ Dent. 2006 Jul; 27(7):384-388. 16. Toffler M, Toscano N, Holtzclaw D, Corso MD, Dohan Ehrenfest DM. Introducing Choukroun’s platelet rich fibrin (PRF) to the reconstructive surgery milieu. J Implant Clin Adv Dent. 2009;1:21–30. 17. Bains R, Bains VK, Loomba K, Verma K, Nasir A. Management of pulpal floor perforation and grade II Furcation involvement using mineral trioxide aggregate and platelet rich fibrin: A clinical report. Contemp Clin Dent. 2012;Sep; 3(Suppl 2):S223–S227. 18. Simonpieri A, Del Corso M, Vervelle A, Jimbo R, Inchingolo F, Sammartino G, Dohan Ehrenfest DM.. Current knowledge and perspectives for the use of platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) in oral and maxillofacial surgery part 2: Bone graft, implant and reconstructive surgery. Curr Pharm Biotechnol.2012;13(7):1231–1256.  19. Singh S, Singh A, Singh S,  Singh R. Application of PRF in surgical management of periapical lesions. Natl J Maxillofac Surg. 2013;4 (1): 94–99. 20. Anantula K, Annareddy A. Platelet-rich fibrin (PRF) as an autologous biomaterial after an endodontic surgery: Case reports. J Dr NTR Univ Health Sci. 2016;5(1):49-54. 21. Sharma S, Sikri V, Sharma NK, Sharma VM. Regeneration of tooth pulp and dentin : trends and advances. Annals of Neurosciences. 2010;17(1). http://annalsofneurosciences. org/journal/index.php/annal/article/viewArticle/ans.09727531.2010.170104/853. Accessed January 19, 2017. 22. Huang FM, Yang SF, Zhao JH, Chang YC. Platelet-rich fibrin increases proliferation and differentiation of human dental pulp cells. J Endod. 2010; 36(10):1628-1632.

Conclusion Regenerative endodontics is a tissueengineering process that requires the following three elements to succeed: 1. Scaffold 2. Growth factors 3. Stem cells21 PRF provides a 100% bio-compatible, natural scaffold enriched with growth factor that can help with the proliferation and differentiation of human dental pulp cells.22 Further research and clinical trials are needed to understand the benefits and applications of PRF in endodontics. EP

Acknowledgment The author would like to thank Dr. Calvin Tae Nam for his great help and inspiration.

REFERENCES 1. Choukroun J, Adda F, Schoeffler C, Vervelle A. Une opportunité en paro-implantologie: Le PRF. Implantodontie. 2001;42:55–62. 2. Dohan DM, Choukroun J, Diss A, Dohan SL, Dohan AJ, Mouhyi J, Gogly B. Platelet-rich fibrin (PRF): a secondgeneration platelet concentrate. Part II: platelet-related biologic features. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2006;101(3):e45–e50. 3. Dohan Ehrenfest DM, de Peppo GM, Doglioli P, Sammartino G. Slow release of growth factors and thrombospondin-1 in Choukroun’s platelet-rich fibrin (PRF): a gold standard to achieve for all surgical platelet concentrates technologies. Growth Factors. 2009;27(1):63–69. 4. Khiste SV, Tari RN. Platelet-Rich Fibrin as a Biofuel for Tissue Regeneration. ISRN Biomaterials. Vol. 2013, Article ID 627367, 6 pages, 2013. doi:10.5402/2013/627367. 5. Borie E, García Oliví D,  Orsi IA, Garlet K, Weber B, Beltrán V, Fuentes R. Platelet-rich fibrin application in dentistry: a literature review. Int J Clin Exp Med. 2015;8(5):7922–7929.

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network, short duration of growth factor release, potential allergic reaction to bovine thrombin additive, and cost make PRP much less attractive when compared to PRF. Minsk and Polson15 suggested that root resection can be a valuable procedure when the tooth in question has a very high strategic value or when there are specific problems that cannot be solved by other therapeutic approaches. Teeth in proximity to anatomic landmarks, such as the maxillary sinus, can be treated safely by root resection therapy. In this case study, bone grafting the root area after the mesial buccal root amputation helped maintain bone height and prevent ridge deficiency. The tooth has no mobility, and crestal bone levels are excellent in the months following the procedure. The 7-month follow-up shows good bone healing with full gingival architecture resulting in minimal food impaction and easier homecare. Other applications of PRF in endodontics include regenerative endodontics,6 sinus membrane repair,16 perforation repair procedures,17 hard/soft tissue grafting of large defects, and socket preservation procedures.4,18,19, 20


Antibacterial effectiveness of ozone gas and highfrequency electrical pulses over Enterococcus faecalis Drs. Tiago André Fontoura de Melo, Karen Barea de Paula, Francisco Montagner, Alcione Luiz Scur, Liviu Steier, Roberta Kochenborger Scarparo, José Antônio Poli de Figueiredo, and Fabiana Vieira Vier-Pelissera present a study into endodontic disinfection effectiveness Abstract


The present study evaluated the effect of ozone gas (OZY® system) and highfrequency electrical pulses (Endox® system), over Enterococcus faecalis cells. Forty plastics tubes were filled with 30 µL of E. faecalis (ATCC 29212) suspension and were divided into four experimental groups, according to the disinfection. Protocol: Group 1 — E. faecalis suspension (no disinfection protocol) (Control Group); Group 2 — suspension + OZY® system, a pulse-120-second (Endox®); Group 3 — suspension + OZY® system, four 24-second pulses (Endox®); Group 4 — suspension + Endox® system alone as disinfection. After each specific disinfection protocol, 20 µL of contaminated BHI broth was analyzed for CFU counting. In the first analysis (M1), 10 µL of contaminated BHI was plated over BHI agar and incubated at 37ºC for 24 hours. The other 10 µL remaining was placed into a plastic tube and incubated for 7 days. Then an aliquot of the broth was placed on agar, and CFU counting was also performed (M2). Statistical analysis was carried out. The significance level was set at 5%. The disinfection protocols employed were not able to inactivate the E. faecalis strains in both periods of analysis. The use of ozone gas or high-frequency electric pulses was not effective to reduce the E. faecalis load.

The failure of endodontic treatment can be associated with disinfecting procedures performed within the root canal that do not effectively promote the control and elimination of infection (Lima, et al., 2015). Some microorganisms, such as E. faecalis can remain viable within the root canal system, even after completion of the mechanical chemical preparation (Siqueira, et al., 2000) and the use of an intracanal medication and irrigation for canal disinfection (Evans, et al., 2002). E. faecalis has inherent antimicrobial resistance, the ability to adapt to harsh environmental changes, and the ability to invade into the dentinal tubules. Therefore, they remain protected and are difficult to eliminate (Zhang, et al., 2015). They are facultative anaerobes, possessing the ability to grow in the presence or absence of oxygen (Rôças, et al., 2004). E. faecalis overcomes the challenges of survival within the root canal system in several ways. It has the capacity to endure prolonged periods of starvation until an adequate nutritional supply becomes available (Figdor, et al., 2003). E. faecalis is able to survive in areas of high pH produced by Ca(OH)2, due to a proton-pump mechanism (Evans, et al., 2002). According to Vianna, et al. (2009), some bacteria may proliferate in pH around 7 and that an increase or decrease of pH can cause reversible and temporary inactivation. However, once re-established to the ideal pH, it returns to its metabolic activities. So far, some substances and intracanal medication can act over the E. faecalis in reversible form for a certain period, but not kill it.

Drs. Tiago André Fontoura Francisco Montagner, and are from the Department University of Rio Grande RS, Brazil.

de Melo, Karen Barea de Paula, Roberta Kochenborger Scarparo of Restorative Dentistry, Federal do Sul (UFRGS), Porto Alegre,

Drs. José Antônio Poli de Figueiredo and Fabiana Vieira VierPelisser are from the Clinical Department, Postgraduate Program, Dental School, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Porto Alegre, RS, Brazil. Dr. Alcione Luiz Scur is in Private Practice, Gramado, RS, Brazil. Dr. Liviu Steier is from the Postgraduate Dental Education Unit, Institute of Clinical Education, Warwick Medical School, University of Warwick, Coventry, United Kingdom.

26 Endodontic practice

The ozone in both gaseous and aqueous states is a potent oxidizing agent with antimicrobial effects, already described in the literature (Nagayoshi, et al., 2004). The oxidation of the bacterial cell wall and cytoplasmic membrane affects the osmotic balance, which may result in cell lysis (Bünning, Hempel, 1996). Likewise, the use of highfrequency electrical pulses system, which applies high-frequency electrical currents, has shown satisfactory results over the microbial membrane (Cassanelli, et al., 2008; Aranda-Garcia, et al., 2012). However, it has not been elucidated if they can exert an antimicrobial effect that remains over time. The aim of this study was to evaluate in vitro the effect of ozone gas and highfrequency electrical pulses, over E. faecalis strains in a liquid suspension, as occurs into the main root canal, and to determine if there was a synergetic effect when both disinfection methods were used together and improved bacterial kill resulted.

Materials and methods Sample preparation and contamination Forty plastic tubes (Kasvi, Curitiba, Paraná, Brazil) were previously sterilized in an autoclave (Cristófoli, Curitiba, Paraná, Brazil) for a period of 30 minutes. The strain used in the study was of E. faecalis ATCC 29212. Bacteria grew on a medium of broth BHI (Brain Heart Infusion) for a period of 24 hours at 37°C and 10% CO2 atmosphere in a bacteriological incubator. The number of colony-forming units (CFU/g/mL) on suspension was determined

Table 1 - Description of the experimental groups and disinfection protocols. Experimental Group


Contamination/E. faecalis

Disinfection Protocol

Group 1



Without treatment

Group 2



OZY® system (1 pulse — 120 sec.)

Group 3



OZY® system (4 pulses — 24 sec.) each

Group 4



Endox® system

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Disinfection procedure Disinfection protocols performed in each experimental group were: • Group 1 — Positive Control: the E. faecalis contaminated Eppendorfs did not undergo any disinfection protocol. • Group 2 — OZY® system/1 pulse: the tip of the OZY® system was introduced inside the Eppendorfs, just one 120-second-long pulse was delivered, as described by Kustarsi, et al., (2009). • Group 3 — OZY® system/4 pulses: the OZY® system was introduced inside the s, and four 24-second pulses

each were delivered, according to Case, et al. (2012). There was a 5 second interval between pulses. Due to the unavailability of a specific tip to use with the OZY® system (Endox SRL, Italy) for root canal treatment, a device was developed for the “Oto” tip. This adapter was made of 420 surgical steel with 0.20 mm diameter at the end and 30 mm length (Figure 1). The OZY® system was operated with 5 N intensity, according to the manufacturer’s instructions. The only variation was in the device activation time between the OZY® 1 pulse and OZY® 4 pulse groups. • Group 4 — Endox®: the protocol for the use of Endox® system (Lysis SRL, Milan, Italy) (Figure 2) employed in the experiment was the same as described by Lendini, et al., (2005). The device black probe (measuring 30 mm in length and 0.20 mm in diameter) was introduced inside the Eppendorfs. Four 600 kHz pulses were delivered inside each tube with a 1/10 of a second standard time for each application.

first analysis (M1), 10 µL of contaminated BHI were plated in Agar BHI and incubated at 37ºC for 24 hours. The remaining 10 µL were placed in a plastic tube and incubated for 7 days. Then the inoculated agar plates were analyzed (M2). The CFU values were recorded and inserted into a spreadsheet.

Microbial counts analysis After performing disinfection protocols inside the laminar flow chamber, 20 µL of BHI broth contaminated with E. faecalis were collected with the aid of a micropipette. At


Statistical analysis Comparisons between groups and moments were performed using non-parametric tests (Wilcoxon T, Kruskal-Wallis H, and Mann-Whitney U for post hoc procedures). No adjustments were made for multiple comparisons. Significance level was set at α = 0.05. Analyses were conducted using SPSS version 22.0 (SPSS Inc, Chicago, Illinois).

Results The results are expressed in Table 2. There was no statistical difference between the media of CFU/mL disinfection protocols employed. None of the disinfection methods was effective to reduce the E. faecalis CFU count.

The complete eradication of microorganisms through the endodontic treatment protocols is difficult (Atila-Pektaş, et al., 2013). A possible justification for this difficulty up until this point is that many of the therapeutic ways to disinfect are unable to inactivate the active power of bacterial strains. Vianna, et al., (2009) and Mehrvarzfar, et al., (2011) reported that after a few hours of the action of different substances, there had been growth of E. faecalis strains. The

Figure 1: Oto tip of the OZY® system with surgical steel connected Table 2: Comparative table of the media CFU/mL and the p value of the four experimental groups in relation to two analysis moments Experimental Group

M1 (n=10)

M2 (n=10)


Group 1



> 0.99

Group 2




Group 3




Group 4






> 0.99



Medium followed by distinct lowercase letters had a statistically significant difference. NC: not computable (very high value to count).

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Figure 2: Endox® system used in the study Endodontic practice 27


by plate count agar containing blood. The suspension of E. faecalis was diluted up to 10-8 in 0.85% saline and 100 µL of 10-6, 10-7, and 10-8 suspension concentration. The strains were seeded on blood agar plates in duplicate, using a sterile Drigalsky rod, and plates were incubated at 37°C for 24 hours. After this period, a count of CFU/mL of boards was performed in order to check the growth of 15 to 150 colonies. Bacterial density ranged from 4.0 x 108 to 7.2 x 108. The tubes were filled with 30 µL of the E. faecalis. The forty Eppendorfs were randomly divided in four experimental groups (Table 1).

CLINICAL RESEARCH tested disinfection protocols only promoted a reversible inactivation of bacteria. They were not able to completely disrupt the E. faecalis cells. In the present study, E. faecalis was chosen as the test microorganism because it is one of the most resistant microorganisms found in infected root canals (Sedgley, et al., 2008), and it has been reported that cases with refractory endodontic treatment were associated with this bacterial strain (Stuart, et al., 2006). The analysis after performing disinfection protocols demonstrated a significant reduction in the level of CFU using an ozone gas system in relation to the high-frequency electrical pulses. This finding is consistent with the study by Virtej, et al., (2007) in which the Endox® system presented a less antimicrobial effect than sodium hypochlorite, BioPure MTAD®, and the ozone gas HealOzone® system. Although some studies, such as Cassanelli, et al. (2004), Hubbezoglu, et al. (2014), and Kaptan, et al. (2014), have demonstrated a bactericidal effect of ozone gas and high-frequency electrical pulses equipment, none of the disinfection protocols carried out in the study promoted a significant elimination of the E. faecalis cells. According to Virtej, et al., (2007), Kustarci, et al. (2009), Karale, et al. (2011), and Zan, et al. (2013), the antibacterial effect of the aqueous ozone and high-frequency electrical pulses was insufficient when compared with the sodium hypochlorite solution. In addition, in the second period (M2), 7 days after collection, there was an increase in the CFU counts when compared to the control group and immediately after the disinfection protocols. The study of Virtej, et al. (2007), observed bacterial growth after a week of incubation. It reaffirms that both protocols of disinfection were able to inactivate the bacteria but only for a short period of time. Once re-established, the environmental condition, microorganisms, and metabolic activities returned normally. Data obtained in the study of ArandaGarcia, et al. (2012), are in accordance with the considerations reported in this experiment. The authors compared the effectiveness of antibacterial Endox Plus® system and the 2.5% sodium hypochlorite solution in combination with BioPure MTAD® or EDTA on root canals infected with E. faecalis. Although the data have initially been satisfactory, all disinfection procedures allowed the bacterial recovery 7 days after treatment. It 28 Endodontic practice

The results obtained in the study reinforce the importance of finding new alternatives for greater effectiveness in the process of endodontic disinfection. demonstrated the persistence and viability of bacteria inside the root canal system. Polydorou, et al. (2006), observed bacterial growth 8 weeks after the use of the HealOzone® system. According to Cassanelli, et al. (2008), the high-frequency electrical pulses system induces pore formation and other defects in the membrane of the exposed bacteria. Nagayoshi, et al. (2004), noted that ozone gas has the power to damage the bacterial membrane by tissue oxidation, thus increasing its permeability. Therefore, both systems may exert reversible inactivation on the bacterial cell membrane. However, the restoration of bacterial environment and

REFERENCES 1. Aranda-Garcia AR, Guerreiro-Tanomaru JM, Faria-Júnior NB, et al. Antibacterial effectiveness of several irrigating solutions and the Endox Plus system - an ex vivo study. Int Endod J. 2012;45(12):1091-1096. 2. Atila-Pektaş B, Yurdakul P, Gülmez D, Görduysus O. Antimicrobial effects of root canal medicaments against Enterococcus faecalis and Streptococcus mutans. Int Endod J. 2013;46(5):413-418. 3. Bünning G, Hempel DC. Vital-fluorochromization of microorganisms using 3’, 6’-diacetylfluorescein to determine damages of cell membranes and loss of metabolic activity by ozonation. Ozone Sci Engl. 1996;18:173-181. 4. Case PD, Bird PS, Kahler WA, George R, Walsh LJ. Treatment of root canal biofilms of Enterococcus faecalis with ozone gas and passive ultrasound activation. J Endod. 2012;38(4):523-526. 5. Cassanelli C, Marchese A, Cagnacci S, Debbia EA. Alteration of membrane permeability of bacteria and yeast by high frequency alternating current (HFAC). Open Microbiol J. 2008;2:32-37.

substrate may have promoted the return of their physiological conditions. The results obtained in the study reinforce the importance of finding new alternatives for greater effectiveness in the process of endodontic disinfection. Perhaps, one of the possibilities would be the association of irrigating solutions with the tested equipment because the damage to the bacterial membrane promoted by them can facilitate and potentiate the antimicrobial action. According to the results of the present study, both ozone gas and the highfrequency electrical pulses were not effective to eliminate E. faecalis, immediately after the disinfection protocol and after 7 days. EP

of high-frequency electrical pulses on organic tissue in root canals. Int Endod J. 2005;38(8):531-538. 14. Lima SM, Sousa MG, Freire MS, Almeida, et al. Immune Response Profile against Persistent Endodontic Pathogens Candida albicans and Enterococcus faecalis In Vitro. J Endod. 2015;41(7):1061-1065. 15. Mehrvarzfar P, Saghiri MA, Asatourian A, et al. Additive effect of a diode laser on the antibacterial activity of 2.5% NaOCl, 2% CHX and MTAD against Enterococcus faecalis contaminating root canals: an in vitro study. J Oral Sci. 2011;53(3):355-360. 16. Nagayoshi M, Fukuizumi T, Kitamura C, Yano J, Terashita M, Nishihara T. Efficacy of ozone on survival and permeability of oral microorganisms. Oral Microbiol Immunol. 2004;19(4):240-246. 17. Polydorou O, Pelz K, Hahn P. Antibacterial effect of an ozone device and its comparison with two dentin-bonding systems. Eur J Oral Sci. 2006;114(4):349-353. 18. Rôças IN, Siqueira JF, Santos KRN. Association of Enterococcus faecalis with different forms of periradicular diseases. J Endod. 2004;30(5):315-320.

6. Cassanelli C, Roveta S, Cavallini F, Marchese A, Debbia EA, Armanino R. Bactericidal effect of endox against various pathogens. 14th ECCMID; 2004; Prague, Czech Rep. Abstr. P480.

19. Sedgley CM, Lee EH, Martin MJ, Flannagan SE. Antibiotic resistance gene transfer between Streptococcus gordonii and Enterococcus faecalis in root canals of teeth ex vivo. J Endod. 2008;34(5):570-574.

7. Evans M, Davies JK, Sundqvist G, Figdor D. Mechanisms involved in the resistance of Enterococcus faecalis to calcium hydroxide. Int Endod J. 2002;35(3):221-228.

20. Siqueira JF Jr, Rôças IN, Favieri A, Lima KC. Chemomechanical reduction of the bacterial population in the root canal after instrumentation and irrigation with 1%, 2.5%, and 5.25% sodium hypochlorite. J Endod. 2000;26(6):331-334.

8. Figdor D, Davies JK, Sundqvist G. Starvation survival, growth and recovery of Enterococcus faecalis in human serum. Oral Microbiol Immunol. 2003;18(4):234-239. 9. Hubbezoglu I, Zan R, Tunc T, Sumer Z. Antibacterial Efficacy of Aqueous Ozone in Root Canals Infected by Enterococcus faecalis. Jundishapur J Microbiol. 2014;7(7):e11411. 10. Kaptan F, Güven EP, Topcuoglu N, Yazici M, Külekçi G. In vitro assessment of the recurrent doses of topical gaseous ozone in the removal of Enterococcus faecalis biofilms in root canals. Niger J Clin Pract. 2014;17(5):573-578. 11. Karale R, Thakore A, Shetty V. An evaluation of antibacterial efficacy of 3% sodium hypochlorite, high-frequency alternating current and 2% chlorhexidine on Enterococcus faecalis: An in vitro study. J Conserv Dent. 2011;14(1):2-5. 12. Kustarci A, Sümer Z, Altunbaş D, Koşum S. Bactericidal effect of KTP laser irradiation against Enterococcus faecalis compared with gaseous ozone: an ex vivo study. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2009;107(5):e73-e79. 13. Lendini M, Alemanno E, Migliaretti G, Berutti E. The effect

21. Stuart CH, Schwartz SA, Beeson TJ, Owatz CB. Enterococcus faecalis: its role in root canal treatment failure and current concepts in retreatment. J Endod. 2006;32(2):93-98. 22. Vianna ME, Zilio DM, Ferraz CC, Zaia AA, de Souza-Filho FJ, Gomes BP. Concentration of hydrogen ions in several calcium hydroxide pastes over different periods of time. Braz Dent J. 2009;20(5):382-388. 23. Virtej A, MacKenzie CR, Raab WH, Pfeffer K, Barthel CR. Determination of the performance of various root canal disinfection methods after in situ carriage. J Endod. 2007;33(8):926-929. 24. Zan R, Hubbezoglu I, Sümer Z, Tunç T, Tanalp J. Antibacterial effects of two different types of laser and aqueous ozone against Enterococcus faecalis in root canals. Photomed Laser Surg. 2013;31(4):150-154. 25. Zhang C, Du J, Peng Z. Correlation between Enterococcus faecalis and persistent intraradicular infection compared with primary intraradicular infection: a systematic review. J Endod. 2015;41(8):1207-1213.

Volume 10 Number 1


Anatomical shaping with XP 3-D Shaper and Finisher Dr. Allen Ali Nasseh discusses nonsurgical retreatment with innovative instruments


ickel titanium has been a miracle alloy in the past few decades. Since its discovery by the Naval Ordinance in 1958 during attempts to develop the ideal alloy for ballistic missile nose cones, to its adaptation in medicine in the 1980s for cardiac stents, and later for endodontic files and orthodontic wires, this alloy has seen lots of modifications. Each modification has aimed to extract the best physical properties for a specific application. The latest patented formulation of this alloy has yielded a unique wire that combined with a unique instrument design, can help solve a very specific, but important endodontic problem — the problem of cleaning oval canals with round endodontic files! We know that human root canals are primarily oval, possessing a major diameter as a well as a minor diameter. Historically, however, endodontic instruments have evolved to cut round holes in these oval canals (Figure 1). As a result, large areas of the canal have remained untouched despite vigorous instrumentation and irrigation. Furthermore, rotary and reciprocating motions have packed the cut debris from the root canal in the oval areas preventing adequate cleaning and disinfection of this space. The application of the newly patented NiTi alloy called MaxWire (Brasseler USA®, Savannah, Georgia) with the special ability to

Allen Ali Nasseh, DDS, MMSc, received his dental degree from Northwestern University Dental School in Chicago, Illinois, in 1994 and completed his postdoctoral endodontic training at Harvard School of Dental Medicine in 1997, where he also received a Masters in Medical Sciences (MMSc) degree in the area of bone physiology. He has been a clinical instructor and lecturer in the postdoctoral endodontic program at Harvard School of Dental Medicine since 1997 and the Alumni Editor of Harvard Dental Bulletin. Dr. Nasseh is the President and Chief Executive Officer for the endodontic education company Real World Endo® ( He is the endodontic advisor to several educational groups and study clubs and is endodontic editor to several peer-reviewed journals and periodicals. He has published numerous articles and lectures extensively nationally and internationally in surgical and nonsurgical endodontic topics. Dr. Nasseh is in solo private practice ( in downtown Boston, Massachusetts.

30 Endodontic practice

Figure 1: 1A. Root canals are oval and have a major and minor diameter (a and b). 1B. Traditional endodontics has attempted to use round instruments in oval canals and has therefore only been able to reach the minor diameter of the canal, leaving large areas untouched

Figure 2: Once rotated, the 3D Shaper and Finisher instruments turn into corresponding shape bottle brushes used for specific actions of cleaning irregular and oval-shaped canals. The up-and-down motion cleans the walls. The size 30 tip and the .01 taper of the shaper and the size 25/30 tip with 00 taper of the Finisher make them both flexible while allowing them to get into the oval areas of the canal leaving a large chip space and light engagement

shift crystalline structure at body temperature in order to adapt to the root canal wall, has provided a unique instrument with the promise of anatomical shaping. Anatomical shaping is the process of shaping by enlarging the natural cross-sectional shape of the root in all directions, rather than forcing a round-shaped rotary file into an oval canal, which results in too much cleaning in some areas of the canal and not enough elsewhere. The newly released XP 3-D Shaper and Finisher™ instruments (Brasseler USA, Savannah, Georgia) are unique in their ability to shape canals or enhance

irrigation while using the MaxWire’s adaptive core technology. MaxWire alloy has been designed to go through a martensitic transformation at temperatures above 35 degrees Celsius. This temperature represents the body temperature inside the root canal and allows the instrument to shape shift from a relatively straight and very malleable shape at room temperature, where the alloy is in its martensitic phase (M-Phase), to a more robust and serpentine shape at body temperature, when the metal transforms into its austenitic phase (A-Phase). As a result of this temperature-driven transformation, Volume 10 Number 1

Apical Periodontitis. The probing was normal around the tooth. Although the previous root canal therapy was performed 2 years previously and looked adequate, apicoectomy was deemed risky due to the length of the root and the difficult access to the area. As a result, a nonsurgical retreatment was recommended. The patient accepted the treatment plan, and following mandibularblock anesthesia, the tooth was isolated and access made through the gold crown. The root canal fillings were identified in all canals through the crown, and the coronal half of the gutta percha was removed in each root using an ESX® Orifice Opener (Brasseler USA, Savannah, Georgia) and heat. Chloroform was then used in combination with a descending order of sizes 40-30 ESX® Files (Brasseler USA, Savannah, Georgia) in single stroke and clean motion. Once working length was achieved and measured using EndoSync™ A.I. (Brasseler USA, Savannah, Georgia), patency was confirmed in all three canals, and gutta percha was removed to a

Figure 3: A previously endodontically treated tooth with symptomatic apical periodontitis was referred for treatment

Figure 4: Radiograph at the end of the first visit showing great adaptation of Ca(OH)2 in the root canal all the way to the apex

Volume 10 Number 1

These instruments will likely prove to be a welcome addition to conventional and retreatment endodontics.

size 40/04 ESX File in all canals. Following thorough irrigation and ultrasonic use, some small gutta-percha tags were visible on the canal walls. The canal was then flooded with sodium hypochlorite, and the 3D Finisher R file was used at 800 rpm (1.0Ncm torque) for three 20-second intervals with 4 mm-7 mm-long strokes up and down each canal. Each 20-second interval was followed by irrigation in the canal, where a large amount of debris and shredded gutta percha was observed to irrigate out of the canal. Following this protocol, the gutta-percha tags on the wall that were observed with the microscope but could not be removed with the ultrasonic and conventional instrumentation were no longer visually present. Calcium hydroxide therapy was performed for additional disinfection prior to obturation. The Finisher was also used to take the Ca(OH)2 to the full working length and coat the walls. The instrument was used at a lower rpm (300) to coat the walls, and a postoperative Ca(OH)2 radiograph was taken (Figure 4). The patient returned 2 weeks later to complete the retreatment procedure. The patient’s symptoms had completely resolved. The patient claimed experiencing no postoperative pain after his first visit. The tooth was isolated and accessed. The calcium hydroxide was removed with irrigation followed by the use of the 3D Shaper to length using the instrument for 20 seconds in each canal followed by irrigation. A radiograph was taken to confirm the removal of the Ca(OH)2 (Figure 5). The XP 3D Shaper was then used in each canal for 10 up-and-down strokes. Irrigation

Figure 5: Radiograph after removal of the Ca(OH)2 with the help of the 3D Finisher R showing clean canals and removal of the Ca(OH)2 from all canals Endodontic practice 31


the instrument is more flexible and straight at room temperature but becomes an efficient cutting instrument at body temperature when the file design expands to engage a much wider envelope of motion than the file at room temperature. Both instruments operate at 800-1,000 rpm and can be used on a standard rotary handpiece. The rotation of this adaptive shape at body temperature inside a root canal transforms this instrument into a virtual bottle brush with the capacity of touching the surfaces of the root canal in all directions (Figure 2). Due to its thin core and extreme flexibility (1% taper for the Shaper and no taper for the Finisher instrument), the instrument can fit inside the oval and bounce off the walls touching all surfaces and cutting or scraping dentin. The main difference between the two 3D instruments is that the Finisher essentially functions like a small plastic bottle brush, and the Shaper functions like a tapered metal brush. Therefore, the Finisher scrubs irregularly shaped walls of the root canal during up-and-down motion while the Shaper actually cuts dentin and creates a tapered shape while using the same motion. In this article, I would like to share a recently treated nonsurgical retreatment case where both the 3D Finisher and Shaper were utilized to facilitate and expedite various phases of instrumentation. A symptomatic mandibular left second molar was referred to for evaluation (Figure 3). Following thorough clinical examination and testing, the tooth was diagnosed with a pulpal diagnosis of previous endodontic therapy with Symptomatic


Figure 6: Cone fitting of the 40 and 55/04 bioceramic-coated gutta-percha cones until light tug-back was achieved in all canals

confirms removal of additional debris from the root canal. Canals were then dried using paper points, and constant tapered 40 and 55/04 EndoSequence® BC gutta-percha cones (Brasseler USA, Savannah, Georgia) were fitted to length and confirmed radiographically (Figure 6). The cones were then cemented using EndoSequence® BC Sealer™ (Brasseler USA, Savannah, Georgia) to full length and hydraulically condensed after searing off at the orifice. The access was temporized. An immediate and 1 month follow-up radiograph was obtained, and patient’s resolution of clinical symptoms were confirmed (Figure 7). The patient will be monitored for bony healing at 6 months postoperatively.

Discussion The use of the size XP Finisher to remove the remaining GP on the oval aspects of the root canal wall after removing the main GP core with conventional files and its additional use for activating the irrigant and touching the canal walls to remove the biofilm and place and remove Ca(OH)2 effectively in the canal has been shown scientifically as an effective modality.1-7 The ability to place the sealer accurately while coating the walls completely is also very useful in such cases. Furthermore, the size 30 Finisher acts as great tool for retreatment of hydraulically condensed roots with bioceramic in the oval aspect of the canal. Clinically, the 3D instruments are user-friendly and do not require additional armamentarium for their implementation. The use of the XP 3D Shaper and Finisher to do anatomical shaping through the adaptive alloy technology and their ability 32 Endodontic practice

Figures 7A and 7B: Final postoperative radiograph showing adequate radiographic results with great wall adaptation despite the use of hydraulic condensation and confirmation of resolution of clinical symptoms 1 month postoperatively

to touch root canal walls beyond the reach of conventional files will likely prove to be a welcome addition to conventional and retreatment endodontics. Further research is needed in this area, but the initial clinical experience and outcomes of this technology appear very promising. EP

REFERENCES 1. Bao P, Shen Y, Lin J, Haapasalo M. In Vitro Efficacy of XP-endo Finisher with 2 Different Protocols on Biofilm Removal from Apical Root Canals. J Endod. 2017;43(2):321325. Epub 2016 Dec 7. 2. Keskin C, Sariyilmaz E, Sariyilmaz Ö. Efficacy of XP-endo Finisher File in Removing Calcium Hydroxide from Simulated Internal Resorption Cavity. J Endod. 2017;43(1):126-130. 3. Wigler R, Dvir R, Weisman A1, Matalon S, Kfir A1. Efficacy of XP-endo finisher files in the removal of calcium hydroxide paste from artificial standardized grooves in the apical third

of oval root canals. Int Endod J. 2016; Jun 8 [epub ahead of print]. 4. Alves FR, Marceliano-Alves MF, Sousa JC, Silveira SB, Provenzano JC, Siqueira JF Jr. Removal of Root Canal Filling in Curved Canals Using Either Reciprocation Singleor Rotary Multi-instrument Systems and a Supplementary Step with the XP-Endo Finisher. J Endod. 2016; 42(7):1114-1119. 5. Sanabria-Liviac D, Moldauer BI, Garcia-Godoy F, AntonioCampos A, Casaretto M, Torres-Navarro J, Scalercio JM. Comparison of the XP-Endo Finisher File System and Passive Ultrasonic Irrigation (PUI) on Smear Layer Removal after Root Canal Instrumentation Effectiveness of Two Irrigation Methods on Smear Layer Removal. J Dent Oral Health. 4: 1-7. 6. Leoni GB, Versiani MA, Silva-Sousa YT, Bruniera JF, Pécora JD, Sousa-Neto MD. Ex vivo evaluation of four final irrigation protocols on the removal of hard-tissue debris from the mesial root canal system of mandibular first molars. Int Endod J. 2016;Mar 18. DOI:10.1111/iej.12630 [epub ahead of print]. 7. Azim AA, Aksel H, Zhuang T, Mashtare T, Babu JP, Huang GT. Efficacy of 4 Irrigation Protocols in Killing Bacteria Colonized in Dentinal Tubules Examined by a Novel Confocal Laser Scanning Microscope Analysis. J Endod. 2016; 42(6):928-934.

Volume 10 Number 1





Underprepared Canal Anatomically Prepared Canal


Visit our website at To order call 800.841.4522 or fax 888.610.1937. In Canada call 800.363.3838 Patents Pending


Featuring Brasseler’s exclusive MaxWire® Technology, the XP-3D adapts to the canal’s natural anatomy by expanding once exposed to body temperature.


Overprepared Canal



The benefits and limitations of CBCT Dr. Alix Davies discusses the use of CBCT in endodontics


one beam computed tomography (CBCT) is one of the most significant advances in endodontics in the last decade. When used appropriately, it can greatly enhance the diagnosis and treatment planning of a variety of endodontic cases. However, it is important that each case is considered individually to ensure that the benefits provided by the scan outweigh the risks of the additional radiation. Recent European Society of Endodontology (ESE) guidelines (Patel, et al., 2014) on the use of CBCT in endodontics suggest scenarios where a scan may be useful (Table 1). This article aims to explore these scenarios, discussing situations where CBCT would be useful, and those where it would provide no additional benefit to management of the case.

CBCT technology Radiographic examination is essential in the diagnosis and management of endodontic problems and is performed with a periapical radiograph. However, a single periapical has limited diagnostic ability due to anatomical noise from superimposed structures, such as the maxillary sinus, zygomatic arch, and inferior dental nerve (Huumonen, Ørstavik, 2002; Patel, et al., 2009). The three-dimensional anatomy is compressed into a two-dimensional image, which will result in superimposition of the roots and prevent full appreciation of the root canal anatomy. Apical periodontitis is also difficult to diagnose in periapical radiographs when the lesions are confined to cancellous bone, especially when covered by a thick cortical plate (Bender, Seltzer 1961; Huumonen, Ørstavik, 2002).

Educational aims and objectives

This clinical article aims to explain the benefits and limitations of CBCT and digital imaging in endodontics.

Expected outcomes

Endodontic Practice US subscribers can answer the CE questions on page 39 to earn 2 hours of CE from reading this article. Correctly answering the questions will demonstrate the reader can: •

Identify some differences in the diagnostic abilities of 2D- and 3D-imaging technologies.

Identify the technology behind CBCT imaging.

Realize the management of CBCT in endodontics.

Recognize the benefits and limitations of CBCT.

Recognize the importance of assessing patients on an individual basis.

A CBCT is an extraoral imaging technique involving a cone-shaped beam and radiographic detector, which orbit around the patient. The data that is collected is reconstructed to produce three-dimensional scans of the maxillofacial region. These can be viewed in multiple planes to assess the presence of periapical lesions, root canal morphology, and the surrounding dentoalveolar anatomy. This increased knowledge may influence management decisions and treatment approaches (Davies, et al., 2015; Davies, et al., 2016; Patel, et al., 2009). The effective dose of a periapical radiograph is 1-5µSv (Gijbels, et al., 2002) while the dose of CBCT with the Accuitomo (J. Morita USA) (4x4 cm field of view) ranges from 13µSv to 44µSv (Loubele, et al., 2009). The radiation dose received by the patient varies depending on the field of view (FOV), exposure time, tube current and potential,

and the region of the jaw that is undergoing the scan. Clinicans who order CBCT scans must have appropriate training (Brown, et al., 2014) and must ensure that radiation doses to patients are as low as reasonably achievable (ALARA). The need for a CBCT must be justified, due not only to the additional radiation that the patient will be exposed to, but also to the extra cost, and possibly travel time required for the patient to undergo the scan. Increasing numbers of dental practices have in-house CBCT scanners. However, many of these were designed for implant and oral surgery assessment, producing larger volume, lower resolution scans that are unsuitable for endodontic cases. Recent models have an endodontic function that enables a small volume higher resolution (75-125µm) scan to be taken. This is necessary to maximize the information gained while minimizing the dose to the patient.

Table 1: European Society of Endodontology guidelines recommending potential situations when CBCT would be beneficial (Patel, et al., 2014) Diagnosis of radiographic signs of periapical pathosis when there are nonspecific signs and/or symptoms

Alix Davies, BDS Hons, MFDS, MJDF RCSEng, MClinDent Endo, MEndo, RCSEd, is a specialist in endodontics and graduated from Guy’s, King’s and St. Thomas’ Dental Institute in 2005. After appointments in general practice and oral and maxillofacial surgery, she served in the Royal Army Dental Corps, both in England and Germany. Dr. Davies attained the rank of Major before leaving to commence specialist training in endodontics at King’s College London. She is an active member of the British Endodontic Society, and her research interests have focused on CBCT. Dr. Davies’ remaining time is divided between working in a specialist endodontic practice in Surrey and her two children.

34 Endodontic practice

Confirmation of non-odontogenic causes of pathosis Assessment and management of complex dentoalveolar trauma, which may not be readily evaluated with conventional radiographic views Appreciation of extremely complex root canal anatomy prior to endodontic treatment or retreatment Assessment of endodontic treatment complications when existing conventional views have yielded insufficient information Assessment and management of root resorption in cases that appear potentially amenable to treatment Presurgical assessment prior to complex periradicular surgery

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Diagnosis of periapical pathology CBCTs are more specific and sensitive in the diagnosis of periapical pathology than periapical radiographs (Stavropoulos, Wenzel, 2007; Ă–zen, et al., 2009; Patel, et al., 2009). They may, therefore, assist in locating an offending tooth when signs and symptoms are inconsistent (Figures 1A-1C). They may also be used to confirm

the absence of an odontogenic etiology and therefore assist in the diagnosis of non-odontogenic causes of pain (Patel, et al., 2015). Diagnosis of vertical root fracture CBCT scans cannot reliably detect small cracks or incomplete vertical root fractures (Chang, et al., 2016). Larger fractures are likely to be evident clinically or on periapical radiographs, and a CBCT would therefore not

Figure 1A: This patient was referred for root canal treatment of his UR6. At presentation, he complained of a recurring abscess adjacent to this tooth. However, the UR6 was not tender to percussion or palpation, and despite having a deep distal filling, it gave a positive response to Endo-Frost. The periapical radiograph showed a radiolucency on the distal root of the UR6. The UR7 had poorly filled root canals, but due to the superimposition of the UR8, UR6 distal root, and proximity of the sinus floor, it was difficult to accurately assess for periapical pathology

Figures 1B and 1C: The sagittal reconstructed CBCT section with removal of the overlying anatomy (B) and coronal section through the mesial root of the UR7 (C) clearly show a periapical area associated with this root due to a poorly filled mesial canal and unfilled separate MB2. Due to the lack of signs and symptoms from the UR6, it was decided that the bone loss around the distal root was likely to be from pus discharge from the UR7. The patient elected to have the UR7 extracted, and the abscess resolved immediately

Figure 2A: This patient had root canal treatments completed on both the UR4 and UR5. He subsequently developed swelling and pus discharging from a sinus tract between the two teeth. Clinical tests assessing tenderness to percussion and palpation, and assessment for localized deep probing depths, failed to identify the problematic tooth. The periapical with gutta percha in the sinus tract also failed to localize the tooth Volume 10 Number 1

be indicated. CBCT is particularly unreliable in detecting vertical root fractures in rootfilled teeth, as the image scatter produced by the root filling will mask the area of the root that needs to be assessed (Patel, et al., 2013). However, the J-shaped radiolucencies that often indicate a root fracture may be more clearly visible once superimposed structures, such as roots, are removed, thus assisting the clinician in reaching a diagnosis (Figures 2A-2E).Â

Figures 2B-2E: Coronal reconstructed sections of the UR5 (B) and UR4 (D) fail to show an area around the UR5, but there is a clear area of interproximal bone loss in the UR4 furcation area. The axial reconstructed section (C) also shows this clearly. A sagittal reconstructed section through the furcation shows the bone loss around the UR4, which tracks down the mesial aspect of the root. This J-shaped lesion is often indicative of a root fracture Endodontic practice 35


The applications of CBCT in endodontics

CONTINUING EDUCATION Dentoalveolar trauma CBCT may be used to assess dentoalveolar trauma in cases where clinical and conventional radiographic assessments are inconclusive (Patel, et al., 2015). Multiple periapicals are currently recommended to assess for fractures (Diangelis, et al., 2012), but these may still fail to show a horizontal fracture if the radiographic beam does not pass directly through the fracture line (Orhan, Aksoy, Kalender, 2010). The exact location of oblique fractures may, in particular, be more clearly diagnosed with CBCT and therefore more appropriately managed (Bornstein, et al., 2009). Patients are likely to find the extraoral CBCT imaging technique far more comfortable than tolerating intraoral beam holders, especially when teeth are mobile or fractured, or there are soft tissue lacerations. Nonetheless, it is important that the request for a CBCT does not delay emergency treatment if the facilities are not immediately available. Assessment of complex root canal anatomy Each tooth demonstrates a variety of canal configurations that must be thoroughly

disinfected to maximize success rates of root canal treatment. An experienced clinician working with a microscope would be expected to identify the canals in the majority of cases, and therefore routine use of CBCT for every case is not justified. However, cases with unusual root formations, such as dens in dente (tooth within a tooth) (Durack, Patel, 2011), multi-rooted lower premolars, C-shaped molars, or cases with excessively curved canals, may benefit from a CBCT scan. A case where the root treatment was performed to a good standard and has still failed may also require additional imaging to assess for unfilled canals (Figures 3A-3F). CBCT has been shown to identify significantly more canals in root-filled teeth than periapicals alone (Davies, et al., 2015). However, scans should not be taken to compensate for lackadaisical diagnostic or clinical skills. It is also important that the clinician has the equipment and skill set to make appropriate use of the additional information gained from the scan. There is little point in taking a CBCT to assess for an unfilled MB2 canal if a lack of magnification and skills would still preclude its discovery. 

Canal sclerosis is a common challenge to adequately disinfecting the canals. CBCT may, however, be of minimal benefit in assisting with the location of the canal as the resolution is significantly worse than that of a periapical radiograph. Therefore, if the radiograph did not reveal a canal, it would be unlikely be visible with CBCT. Assessment of treatment complications CBCT scans are useful to assess complications such as fractured files and perforations. In cases where it is unlikely that a file can be removed, CBCT will provide information about the root canal morphology to determine if the file can be bypassed (Figures 4A-4G). Perforations on a buccal or palatal aspect may also be more clearly assessed with CBCT to determine the most appropriate management technique. Assessment of root resorption Conventional radiographic detection and assessment of root resorption may be challenging. This is compounded if the lesion is on the buccal or lingual/palatal aspect of the

Figures 3A-3C: 3A. Periapical showing a good root filling in the UL6. 3B. Six months later, the patient had mild pain on biting, and the periapical showed an increase in the lesion around the UL6 mesial root. 3C. The axial section of CBCT scan showed an unfilled MB2

Figures 3D-3F: 3D-3E. The patient underwent a CBCT scan, and the sagittal (D) and coronal (E) sections show an unfilled MB2. 3F. Root canal retreatment was performed, and the MB2 was successfully located, disinfected, and obturated 36 Endodontic practice

Volume 10 Number 1

Figures 4E-4G: 4E. Knowledge that the mesiobuccal and distal canals converge enable root canal treatment to be performed, and the file to be bypassed. 4F. Postoperative periapical showing completion of the root canal treatment. 4G. One-year postoperative periapical showing periapical healing of the UL5

tooth where it will be masked by the more radiodense tooth structure. It may also be difficult to distinguish between internal inflammatory and external cervical root resorption from periapicals alone. CBCT has been shown to be significantly more sensitive in detecting resorptive lesions (Estrela, et al., 2009) and also in assisting clinicians with choosing the correct treatment options (Patel, et al., 2009). The buccolingual extent of the resorption and assessment of perforations into the root canal or periodontal ligament can be more easily assessed with a CBCT. This will determine whether conventional treatment, surgery, or a combination of both is required.  This advance knowledge will enable treatment to be completed more efficiently and, in some cases, prevent patients undergoing unnecessary investigations on teeth (Figures 5A-5C). Preoperative CBCT scans Volume 10 Number 1

Figures 5A-5C: 5A. Periapical showing a possible resorption lesion of the LL1. 5B. Sagittal reconstructed CBCT section shows the full extent of the external cervical root resorption and its perforation into the pulp chamber. 5C. Axial reconstructed CBCT section clearly showing the resorption lesion perforating the pulp. This tooth is unsavable Endodontic practice 37


Figures 4A-4D: 4A. Periapical showing a root-filled UL5 with a periapical area and fractured file in one canal. 4B. Sagittal reconstructed CBCT section through the buccal root shows the fractured file to be in buccal root in mesiobuccal canal. There is an additional distobuccal canal that converges with the mesiobuccal canal just beyond the point of instrument fracture. 4C. Sagittal reconstructed CBCT section through the palatal root shows it to also have a periapical area associated with it. 4D. Coronal reconstructed CBCT showing buccal and palatal roots and periapical areas


CBCT is useful in the planning of surgical endodontic procedures, as it will provide accurate information as to the size and location of the periapical lesion and root apex in relation to structures such as the maxillary sinus, inferior dental canal and mental foramen.

should therefore be performed on all teeth with resorptive lesions that are potentially treatable. Surgical planning CBCT is useful in the planning of surgical endodontic procedures, as it will provide accurate information as to the size and location of the periapical lesion and root apex in relation to structures such as the maxillary sinus, inferior dental canal, and mental foramen (Figures 6A and 6B). Additional untreated canals (such as an MB2) may also be located. The amount of destruction of the cortical plates may also be assessed to determine whether membranes and grafting procedures are appropriate.


Figures 6A-6B: 6A. Periapical radiograph of LL5 showing a root-filled tooth with a fractured file fragment in the apical portion. There is a large periapical area associated with this tooth. 6B. CBCT reconstructed images showing the mental foramen in close proximity to the LL5 apex. There is a high risk that the mental nerve could be damaged if root end surgery was performed on the LL5

REFERENCES 1. Bender IB, Seltzer S. Roentgenographic and direct observation of experimental lesions in bone: I. J Am Dent Assoc. 1961;62:152-160. 2. Bornstein MM, Wölner-Hanssen AB, Sendi P, von Arx T. Comparison of intraoral radiography and limited cone beam computed tomography for the assessment of root- fractured permanent teeth. Dent Traumatol. 2009;25:571-577. 3. Brown J, Jacobs R, Levring Jäghagen E, et al. Basic training requirements for the use of dental CBCT by dentists: a position paper prepared by the European Academy of DentoMaxilloFacial Radiology. Dentomaxillofacl Radiol. 2014;43(1). 4. Chang E, Lam E, Shah P, Azarpazhooh A. Cone-beam computed tomography for detecting vertical root fractures in endodontically treated teeth: a systematic review. J Endod. 2016;42(2):177-185. 5. Davies A, Mannocci F, Mitchell P, Andiappan M, Patel S. The detection of periapical pathoses in root filled teeth using single and parallax periapical radiographs versus cone beam computed tomography — a clinical study. Int Endod J. 2015;48(6):582-592. 6. Diangelis AJ, Andreasen JO, Ebeleseder KA, et al.; International Association of Association of Dental Traumatology. International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 1. Fractures and luxations of permanent teeth. Dent Traumatol. 2012;28(1):2-12. 7. Durack C, Patel S. The use of cone beam computed tomography in the management of dens invaginatus affecting a strategic tooth in a patient affected by hypodontia: a case report. Int Endod J. 2011;44(5):474-83. 8. Estrela C, Bueno MR, De Alencar AH, et al. Method to evaluate inflammatory root resorption by using cone beam computed tomography. J Endod. 2009;35(11):1491-1497. 9. Gijbels F, Jacobs R, Sanderink G, et al. A comparison of the effective dose from scanography with periapical radiography. Dentomaxillofac Radiol. 2002;31(3):159-163. 10. Huumonen S, Ørstavik D. Radiological aspects of apical periodontitis. Endod Topics. 2002;1(1):3-25.

38 Endodontic practice

The use of CBCT in endodontics is rapidly increasing. Deciding when a CBCT is clinically necessary is a subject that causes great debate among endodontists. As ionizing radiation is used, it is essential that exposures are kept as low as reasonably achievable. Cases must therefore be assessed on an individual basis to determine whether the additional information from the scan will be beneficial in influencing the management of the case. EP

11. Loubele M, Bogaerts R, Van Dijck E, et al. Comparison between effective radiation dose of CBCT and MSCT scanners for dentomaxillofacial applications. Eur J Radiol. 2009;71(3):461-468. 12. Orhan K, Aksoy U, Kalender A. Cone-beam computed tomographic evaluation of spontaneously healed root fracture. J Endod. 2010;36(9):1584-1587. 13. Özen T, Kamburoğlu K, Cebeci AR, Yüksel SP, Paksoy CS. Interpretation of chemically created periapical lesions using 2 different dental cone-beam computerized tomography units, an intraoral digital sensor, and conventional film. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2009;107(3):426-432. 14. Patel S, Dawood A, Whaites E, Pitt Ford T. New dimensions in endodontic imaging: part 1. Conventional and alternative radiographic systems. Int Endod J. 2009;42(6):447-462. 15. Patel S, Dawood A, Wilson R, Horner K, Mannocci F. The detection and management of root resorption lesions using intraoral radiography and cone beam computed tomography - an in vivo investigation. Int Endod J. 2009;42(9):831-838. 16. Patel S, Dawood A, Mannocci F, Wilson R, Pitt Ford T. Detection of periapical bone defects in human jaws using cone beam computed tomography and intraoral radiography. Int Endod J. 2009;42(6):507-515. 17. Patel S, Brady E, Wilson R, Brown J, Mannocci F. The detection of vertical root fractures in root filled teeth with periapical radiographs and CBCT scans. Int Endod J. 2013;46(12):1140-1152. 18. Patel S, Durack C, Abella F, Roig M, Shemesh H, Lambrechts P, Lemberg K. European Society of Endodontology position statement: the use of CBCT in endodontics. Int Endod J. 2014;47(6):502-504. 19. Patel S, Durack C, Abella F, Shemesh H, Roig M, Lemburg K. Cone beam computed tomography in Endodontics — a review. Int Endod J. 2015;48:3-15. 20. Patel S, Wilson R, Dawood F, Foschi F, Mannocci F. The detection of periapical pathosis using digital periapical radiography and cone beam computed tomography in endodontically retreated teeth — part 2: a 1-year post-treatment follow-up. Int Endod J. 2012;45(8):711-723. 21. Stavropoulos A, Wenzel A. Accuracy of cone beam dental CT, intraoral digital and conventional film radiography for the detection of periapical lesions. An ex vivo study in pig jaws. Clin Oral Investig. 2007;11(1):101-106.

Volume 10 Number 1

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The benefits and limitations of CBCT DAVIES

1. __________ has limited diagnostic ability due to anatomical noise from superimposed structures, such as the maxillary sinus, zygomatic arch, and inferior dental nerve. a. A digital photograph b. A CBCT scan c. A single periapical d. A panoramic image 2. ________ is also difficult to diagnose in periapical radiographs when the lesions are confined to cancellous bone, especially when covered by a thick cortical plate. a. Irreversible pulpitis b. Apical periodontitis c. Pulp necrosis d. Condensing osteitis 3. A CBCT is an extraoral imaging technique involving a _______ and radiographic detector, which orbit around the patient. a. cone-shaped beam b. fan-shaped beam c. C-shaped beam d. round beam 4. These (scans) can be viewed in multiple planes to assess ________.

Volume 10 Number 1

a. the presence of periapical lesions b. root canal morphology c. the surrounding dentoalveolar anatomy d. all of the above 5. The radiation dose received by the patient varies depending on _______ and the region of the jaw that is undergoing the scan. a. the field of view (FOV) b. exposure time c. tube current and potential d. all of the above 6. ________ is/are currently recommended to assess for fractures, but these may still fail to show a horizontal fracture if the radiographic beam does not pass directly through the fracture line. a. A single periapical b. Multiple periapicals c. A CBCT d. A transilluminator 7. CBCT has been shown to be ________ in detecting resorptive lesions and also in assisting clinicians with choosing the correct treatment options. a. unreliable

b. not useful c. significantly more sensitive d. significantly less sensitive 8. _________ can be more easily assessed with a CBCT. a. Incomplete vertical root fractures b. The buccolingual extent of the resorption c. Assessment of perforations into the root canal or periodontal ligament d. both b and c 9. Preoperative CBCT scans should therefore be performed _________. a. on all teeth with resorptive lesions that are potentially treatable b. on all teeth c. only on teeth where cracks are suspected d. only on teeth where canal sclerosis is suspected 10. The amount of destruction of the cortical plates may also be assessed to determine whether _______ are appropriate. a. membranes b. grafting procedures c. restorations d. both a and b

Endodontic practice 39




Risk assessment of endodontic-related nerve injuries: part 2 In the final part of two articles, Dr. Tara Renton explores risk assessment, diagnosis, and management of endodontic-related nerve injuries


n part 1 of this clinical article, the author examined the risk factors and consequences of endodontic-related nerve injuries. Here, the author looks at the risk assessment, diagnosis, and management of endodontic-related nerve injuries, as well as recommendations using the literature.

Minimizing risk Risk assessment of the patient and dental factors are very important. Patients over the age of 50 are less likely to recover from nerve injury. Certain medical conditions may predispose your patient to developing chronic post-traumatic neuropathy and/ or pain (existing fibromyalgia, migraines, Raynaud’s disease, IBS, and psychological morbidity). Pre-screening of dental neuropathic pain is advised before undertaking repeated endodontics or further interventional surgery. A key factor in these cases appears to be proximity of the tooth apex to the inferior dental canal (IDC). The mandibular premolars located close to the mental foramina are considered high risk in orthodontics for potential nerve damage (Knowles, Jergenson, Howard, 2003; Baxmann, 2006; Scarano, et al., 2007). An important factor often overlooked in endodontics is the “safety zone,” often referred to during estimation of drilling depths for implant preparation surgery. A single paper addresses the notion that endodontists should consider the distance between the tooth apex and the inferior dental canal (IDC estimated on a plain film not necessarily by a cone beam computed tomography [CBCT]) to ensure that accidental

Educational aims and objectives

This clinical article aims to consider and assess risk factors associated with increased risk of endodontic-related nerve injury.

Expected outcomes

Endodontic Practice US subscribers can answer the CE questions on page 44 to earn 2 hours of CE from reading this article. Correctly answering the questions will demonstrate the reader can: • Consider and assess risk factors associated with increased risk of nerve injury. • Understand the diagnostic features of endodontic-related nerve injuries with particular emphasis on the possible 2- to 3-day delay in presentation after treatment. • Recognize the urgency with which these nerve injuries must be recognized, assessed, and managed if the resolution of nerve injury is too maximized.

Table 1: CBCT radiography may assist in risk assessment for nerve injury related to endodontic treatment chemical leakage Predisposing tooth factor that may result in an adverse incident during root canal treatment

Potential adverse incident if tooth factor not recognized

Resorption defects where extent is not identified such as internal/external communicating with root canal and external surface of the root

Extrusion of endodontic filler/hypochlorite accident

Suspicion of a perforation communicating with the external root surface

Extrusion of endodontic filler/hypochlorite accident

Root fracture where there could be a potential communication of the root canal with external root surface

Extrusion of endodontic filler/hypochlorite accident

Sclerosed root canal

Possible perforation with subsequent hypochlorite accident

Dens invaginatus

Possible perforation with subsequent hypochlorite accident

Periapical lesions and other pathology (cysts)

Neurological injury (may occur if lesion close to inferior dental canal)

Lower molar teeth where root apices are in close proximity to the inferior dental canal and/or mental foramen

Neurological injury (over-instrumentation, overfilling with obturation materials or sealer)

apical leakage or over-instrumentation will more likely cause nerve injury if the apex is adjacent to the IDC (Ngeow, 2010). Assessment of other dental factors, including root fractures and periapical lesions (Table 1) must also be assessed. Assessing

Tara Renton, BDS, MDSc, PhD, FDS, RCS, FRACDS (OMS), FHEA, is a specialist in oral surgery with a particular interest in trigeminal nerve injuries and pain. After completing her oral and maxillofacial surgical training in Melbourne in 1991, Dr. Renton undertook a PhD in trigeminal nerve injury at King’s College London in 1999. She was later appointed senior lecturer at Queen Mary University of London and was then awarded her chair in 2006 at King’s College London. Over the past 7 years, Dr. Renton has led the teaching of dental students, modernizing the oral surgical teaching with minimal access approach and modern local anesthesia techniques. She has established an academic training program, and in collaboration with the Institute of Psychiatry, Psychology & Neuroscience at King’s College London and Imperial College, Dr. Renton has established an international program of trigeminal nerve injury and orofacial pain research.

40 Endodontic practice

the actual position of the IDC, mental loop, and accessory canals can be complex, and the clinician involved in treatment planning must be able to analyze and risk-assess radiological investigations and not leave the risk assessment to another clinician. There continues to be considerable debate as to whether CBCT is superior in assessing these risk factors. Minimizing technical causes Apical extrusion of products may be increased by ultrasonics and minimized by using EndoVac. Postoperative root canal treatment views must be arranged on the day Volume 10 Number 1

of completion of the treatment, and identification of any root canal treatment product in the inferior alveolar nerve (IAN) canal should be reviewed carefully and removed within 48 hours (Helvacıog˘lu Kivanç, 2015). A systematic review made a specific recommendation in care when preventing extrusion of endo materials into the IDC (Olsen, et al., 2014).

CBCT guidance All radiographic examinations must be justified on an individual needs basis whereby the benefits to the patient of each exposure must outweigh the risks. In no case may the exposure of patients to X-rays be considered “routine,” and certainly CBCT examinations should not be done without initially obtaining a thorough medical history and clinical examination. CBCT should only be considered an adjunct to two-dimensional imaging in dentistry (American Association of Endodontists, American Academy of Oral and Maxillofacial Radiology, 2011). Risk assessment — location of the inferior dental canal • A classic study of the relationship between mandibular premolar apices and the mental foramen has reported close proximity with the first premolar apex in 15.4% of patients and with the second premolar apex in 13.9% of patients (Fishel, et al., 1976). • In their morphometric study, Phillips and colleagues reported that each mental foramen was located an average distance of 2.18 mm mesially and 2.4 mm inferiorly from the radiographic apex of the second premolar (Phillips, Weller, Kulild, 1992). • More precisely, each mental foramen was found to be located, on average, anywhere between 3.8 mm mesial, 2.7 mm distal, 3.4 mm above, or 3.5 mm below the apex of the respective second premolar (Phillips, Weller, Kulild, 1992). Volume 10 Number 1

Figure 2: Panoral X-ray illustrating overfill and leakage of endodontic material into inferior dental canal

• In contrast, the apex of each second premolar was between 0 mm and 4.7 mm from the respective mental foramen in various cadaveric studies (Denio, Torabinejad, Bakland, 1992). Is CBCT better than long cone periapical radiographs (LCPA) for risk assessment? Periapical pathology diagnosis using CBCT revealed a significantly lower number of favorable outcomes than periapicals in root canal retreatment. This significantly affected the future management of cases attending for a review (Davies, et al., 2015). In a study by Chavda and colleagues (2014), 21 unsalvageable teeth from 20 patients that had been radiographed and scanned with CBCT imaging were included to look at root fractures. The teeth were atraumatically extracted and visually inspected under a microscope to confirm the presence/ absence of fracture. Both digital radiography and CBCT imaging have significant limitations when detecting vertical root fractures. Is dose reduction possible in CBCT? Limited field-of-view CBCT systems can provide images of several teeth from approximately the same radiation dose as two periapical radiographs, and they may provide a dose savings over multiple traditional images in complex cases. Both 360° and 180° CBCT scans yielded similar accuracy in the detection of artificial bone lesions. The use of 180° scans might be advisable to reduce the radiation dose to the patient in line with the International Commission on Radiological Protection (ICRP) guidance to use as low a dosage as reasonably achievable (Lennon, et al., 2011).

Diagnosis and assessment A previous literature review of paresthesia in endodontics recommended that

the clinician must carry out a complete medical history, panoramic and periapical radiography, and (in some cases) computed tomography, as well as mechanoreceptive and nociceptive tests. It is important to recognize that inferior alveolar nerve injuries (IANI) can occur due to local anesthetic block injections, and the clinician can often discriminate between endodontic and local anesthesia-caused nerve injuries by careful questioning and clinical neurological assessment. Chemical nerve injury may not be obvious radiographically: • If the patient is suffering from neuropathy after the local anesthetic has worn off and the postoperative radiographs confirm that there is no radiopaque material in the canal, chemical nerve injury may be presumed. • Mapping of the neuropathic area will discriminate between inferior dental block (IDB) and endodontic nerve injury. • This may be an irreversible injury to the nerve and subsequent, even swift, removal of the root canal filling or tooth is unlikely to resolve the nerve injury.   • If there is material recognized within the canal, this would suggest injury, but if there is no material in the canal, is the same presumption made? The patients must be assessed holistically, including their history of the event, and if it is related to the initiation of pain. Ensure that the pain history excludes pre-existing neuropathic pain, including: • Severe pain during procedure (funnybone pain) • High level post-surgical pain (indicative of nerve injury) Endodontic practice 41


Figure 1: Abducent and inferior alveolar nerve injury due to endodontic overfill of mandibular molar (image courtesy of S. Ruggiero)

CONTINUING EDUCATION • Ongoing pain, altered sensation and/ or numbness • Functional problems • Psychological issues Important questions about the mechanism and duration of the neuropathy will drive the timing and type of management (Renton, et al., 2006). Necessary investigations include: • Radiological: LCPA; CBCT necessary post-trauma. • Neurosensory to confirm that the presence of a neuropathy and distribution correlates with potential nerve injury. • Diagnostic local anesthesia blocks may be useful in evaluating the potential of some peripheral pain management strategies when medical management is unsuccessful. Management is that of the patient with the nerve injury not the neuropathy itself (Renton, Yilmaz, 2012). Grötz and colleagues (1998) reported on 11 patients with endodontic-associated neuropathy and their management. They similarly reported that the neurological findings were dominated by hypesthesia and dysesthesia, with 50% of patients reporting pain. Initial X-rays showed root filling material in the area of the mandibular canal. Nine cases were treated with apicectomy and decompression of the nerve: In two cases, extraction of the tooth was necessary; only one patient reported persistent pain after surgery. Primarily, all patients should have an apology and explanation (duty of candor) by the treating clinician. Management tools may include counseling for all patients with nerve injuries, which is very effective (there is limited evidence for success of this treatment for endodontic-related IANIs, but evidence does support psychological therapies for chronic pain and IANIs) (Renton, Yilmaz, 2011) for: • Local anesthesia, orthognathic fracture • Endodontic or implant injuries greater than 30 hours • TMS injuries older than 6 months Counseling includes reaffirming nerve injury is permanent and reassurance and explanation. Other management tools include medical symptomatic therapy (pain or discomfort) through topical and systemic agents for pain.  Lastly, surgical exploration is significant: • Remove implant or endodontic material within 24 hours. 42 Endodontic practice

• Explore IAN injuries through socket in less than 4 weeks. • Explore LN injuries before 12 weeks. Surgical management • Repeat endodontic treatment with removal of the overfill or over-instrumentation. There are many reports of repeated endodontic treatment for IANIs related to endodontics; however, the outcomes remain poor (Nayak, et al., 2011; Yatsuhashi, et al., 2003). • Surgical excision of the overfill of chemicals and endodontic root fillers: Pogrel (2007) reported 11 cases of acute surgical intervention with five patients reporting improvement, and two none. On this basis, Pogrel recommends urgent (under 24 hours) surgical exploration with aggressive irrigation and removal of overfill. Several report cases successfully treated using urgent surgical treatment (Scala, et al., 2014; Scolozzi, Lombardi, Jacques, 2004; Brkic´, Gürkan-Köseog˘lu, Olgac, 2009). A similar protocol is recommended for sodium hydroxide neuropathies (Byun, et al., 2015). • Medical management to minimize acute surgical neural inflammation by using NSAIDs and prednisolonemimic protocols undertaken for other acute sensory nerve injuries (Gatot, Tovi, 1986; Grötz, et al., 1998). • Medical management of chronic pain associated with endodontic treatment: Oshima (2009) reported that 16 out of 271 patients presenting with chronic orofacial pain were diagnosed with chronic neuropathic tooth pain subsequent to endodontic retreatment. Most of these patients were treated for maxillary teeth. Seventy percent of the patients responded to tricyclic antidepressant therapy, which highlights the importance of establishing whether the patient has neuropathic pain. In Renton and Yilmaz’s (2012) study, all the patients presented too late for surgical decompression, or it was not indicated. Thus, two patients were managed with oxcarbazepine for neuralgic pain elicited with touch or cold and with topical clonazepam intraorally to manage the severe gingival discomfort.  Two patients were prescribed topical 5% lidocaine patches (12 hours on nocte and 12 hours off daily) for debilitating mechanical

allodynia in the extraoral dermatome of the IAN, causing pain and functional problems. This is a treatment used successfully for patients with chronic orofacial pain, particularly those with mechanical or cold allodynia of the face. Recommendations for treatment of trigeminal neuropathic pain are also well described by Renton and Zakzrewska (2010) (Alonso-Ezpeleta, et al., 2014). Timing of treatment Nerve tissue is incredibly sensitive to pH changes; thus, chemical nerve injuries are commonly permanent and often cause severe neuropathic pain. These chemical nerve injuries often cause severe neuropathic pain. If the patient is suffering from neuropathy after the local anesthesia has worn off, and the postoperative radiographs (not CBCT) confirm that there is no radiopaque material in the canal, chemical nerve injury may be presumed. This may be an irreversible injury to the nerve, and subsequent “swift” removal of the root canal treatment or tooth extraction is unlikely to result in resolution of the nerve injury (Pogrel, 2007).

Management and timing Acute management (greater than 30 hours) Confirm overfill/neuropathy. In some reports, 20% of the nerve injuries are delayed in presentation, and the endodontist may need to warn the patient that onset of altered sensation, pain, and/or numbness up to 3 to 4 days post-endodontic treatment must immediately be reported.  Treatment should be considered within 30 hours of neuropathy presentation to minimize permanency of nerve injury while maximizing resolution. • Consider endodontic retreatment (Yatsuhashi, et al., 2003) • If there is extensive overfill in IDC, refer urgently for extraction, apicoectomy or IAN decompression. Later management If minimal or no symptoms are present, reassure and review (duty of candor). For mild symptoms, such as small neuropathic area, low discomfort: • Reassurance/topical Versatis patches (5% lidocaine patches). • Some authors recommend steroid therapy for early postoperative neuritis (Gatot, Tovi, 1986). For moderate symptoms, such as a larger neuropathic area, functional and Volume 10 Number 1

extrusion of dressing or filling materials into the inferior dental canal or around the mental foramen. • Home check, and if signs of persistent or new neuropathy: remove overfill urgently (30 hours); no antibiotics; recommend vitamin B, NSAIDs, steroids, prednisolone (step down 15 mg for 5 days, 10 mg for 5 days, and 5 mg 5 days), and high dose NSAIDs, 600 mg ibuprofen and make a timely referral to an appropriately

trained neurosurgeon, if necessary; long-term therapeutic management.

Conclusion In this article, the author aims to have highlighted many areas of poor evidence base for prevention, assessment, and management of IANIs related to endodontic treatment; but in addition, focus attention on some areas where improved risk assessment and avoidance of these nerve injuries is possible. EP



1. AAE and AAOMR joint position statement. Use of cone-beam-computed tomography in endodontics. Pa Dent J (Harrisb). 2011;78(1):37-39.

Based on current evidence, dental practitioners undertaking endodontic treatment should: • Not attempt root canal treatment (RCT) in teeth close to the IDC; instead, they should refer for specialist care. • Screen out neuropathic pain pre-RCT. • Risk-assess, including identifying dental risk factors (+/- CBCT case dependent), such as teeth in close proximity to the inferior alveolar nerve, and take special care to prevent overinstrumentation and the extrusion of irrigants and materials into the periapical tissues; root fractures; resorption; apical pathology. • To prevent overfill or extrusion, consider: creating an apical stop or dentin apical plug; make sure the preparation has taper and hence resistance form; obturating shorter; using cold lateral condensation to gain apical control; do not use resinbased sealers such as AH Plus® sealer. • Avoid over-instrumentation: care with instrumentation and patency filing may have to work shorter; care using intracanal medicament (for example, calcium hydroxide) — do not syringe down to full working length; deliver more coronally; use a file to deliver the calcium hydroxide toward the apical part of the canal. • Record any events that may indicate operative nerve injury, including extreme pain during LA IDB, canal instrumentation, irrigation, medication, or filling; and sudden and profuse hemorrhage arising from the apex of the tooth. • Take appropriate postoperative periapical radiographs to check for any

2. Alonso-Ezpeleta O, Martín PJ, López-López J, Castellanos-Cosano L, Martín-González J, Segura-Egea JJ. Pregabalin in the treatment of inferior alveolar nerve paraesthesia following overfilling of endodontic sealer. J Clin Exp Dent. 2014;6(2):e197-e202.

Volume 10 Number 1

3. American Association of Endodontists; American Academy of Oral and Maxillofacial Radiology. Use of cone-beam computed tomography in endodontics Joint Position Statement of the American Association of Endodontists and the American Academy of Oral and Maxillofacial Radiology. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2011;111(2):234-237. 4. Baxmann M. Mental paresthesia and orthodontic treatment. Angle Orthod. 2006;76(3):533-537. 5. Brkić A, Gürkan-Köseoğlu B, Olgac V. Surgical approach to iatrogenic complications of endodontic therapy: a report of 2 cases. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2009;107(5): e50-e53. 6. Byun SH, Kim SS, Chung HJ, et al. Surgical management of damaged inferior alveolar nerve caused by endodontic overfilling of calcium hydroxide paste. Int Endod J. 2016;49(11):1020-1029. 7. Chavda R, Mannocci F, Andiappan M, Patel S. Comparing the in vivo diagnostic accuracy of digital periapical radiography with cone beam computed tomography for the detection of vertical root fracture. J Endod. 2014; 40(10):1524-1529. 8. Denio D, Torabinejad M, Bakland LK. Anatomical relationship of the mandibular canal to its surrounding structures in mature mandibles. J Endod. 1992;18(4):161-165. 9. Fishel D, Buchner A, Hershkowith A, Kaffe I. Roentgenologic study of the mental foramen. Oral Surg Oral Med Oral Pathol. 1976; 41(5):682-686. 10. Gatot A, Tovi F. Prednisone treatment for injury and compression of inferior alveolar nerve: report of a case of anesthesia following endodontic overfilling. Oral Surg Oral Med Oral Pathol. 1986;62(6):704-709. 11. Grötz KA, Al-Nawas B, de Aguiar EG, Schulz A, Wagner W. Treatment of injuries to the inferior alveolar nerve after endodontic procedures. Clin Oral Investig. 1998;2(2):73-76. 12. Helvacıoğlu Kıvanç B, Deniz Arısu H, Yanar NÖ, Silah HM, İnam R, Görgül G. Apical extrusion of sodium hypochlorite activated with two laser systems and ultrasonics: a spectrophotometric analysis. BMC Oral Health. 2015;15(1):71. 13. Kim JH, Yu HY, Park SY, Lee SC, Kim YC. Pulsed and conventional radiofrequency treatment: which is effective for dental procedure-related symptomatic trigeminal neuralgia? Pain Med. 2013;14(3):430-435. 14. Knowles KI, Jergenson MA, Howard JH. Paresthesia associated with endodontic treatment of mandibular premolars. J Endod. 2003;29(11):768-770. 15. Lennon S, Patel S, Foschi F, Wilson R, Davies J, Mannocci F. Diagnostic accuracy of limited-volume cone-beam computed tomography in the detection of periapical bone loss: 360° scans versus 180° scans. Int Endod J. 2011;44(12):1118-1127. 16. Nayak RN, Hiremath S, Shaikh S, Nayak AR. Dysesthesia with pain due to a broken endodontic instrument lodged in the mandibular canal — a simple deroofing technique for its retrieval: case report. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2011;111(2):e48-e51. 17. Ngeow WC . Is there a “safety zone” in the mandibular premolar region where damage to the mental nerve can be avoided if periapical extrusion occurs? J Can Dent Assoc. 2010;76:a61. 18. Ngeow WC, Nair R. Injection of botulinum toxin type A (BOTOX) into trigger zone of trigeminal neuralgia as a means to control pain. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2010;109(3):e47-e50. 19. Olsen JJ, Thorn JJ, Korsgaard N, Pinholt EM. Nerve lesions following apical extrusion of non-setting calcium hydroxide: a systematic case review and report of two cases. J Craniomaxillofac Surg. 2014;42(6):757-762. 20. Oshima K, Ishii T, Ogura Y, Aoyama Y, Katsuumi I. Clinical investigation of patients who develop neuropathic tooth pain after endodontics procedures. J Endod. 2009;35(7):958-961. 21. Patel S, Wilson R, Dawood F, Foschi F, Mannocci F. The detection of periapical pathosis using digital periapical radiography and cone beam computed tomography in endodontically retreated teeth — part 2: a 1-year post-treatment follow-up. Int Endod J. 2012;45(8):711-723. 22. Phillips JL, Weller RN, Kulild JC. The mental foramen: 2. Radiographic position in relation to the mandibular second premolar. J Endod. 1992;18(6):271-274. 23. Pogrel MA. Damage to the inferior alveolar nerve as the result of root canal therapy. J Am Dent Assoc. 2007;138(1):65-69. 24. Renton T, Thexton A, Crean SJ, Hankins M. Simplifying the assessment of the recovery from surgical injury to the lingual nerve. Br Dent J. 2006;200(10):569-573. 25. Renton T, Yilmaz Z. Profiling of patients presenting with posttraumatic neuropathy of the trigeminal nerve. J Orofac Pain. 2011;25(4):333-344. 26. Renton T, Yilmaz Z. Managing iatrogenic trigeminal nerve injury: a case series and review of the literature. Int J Oral Maxillofac Surg. 2012;41(5):629-637. 27. Renton T, Zakrzewska JM: Orofacial pain. In: Shaw I, Kumar C, Dodds C, eds. Oxford Textbook of Anaesthesia for Oral and Maxillofacial Surgery. Oxford:Oxford University Press; 2010. 28. Scala R, Cucchi A, Cappellina L, Ghensi P. Cleaning and decompression of inferior alveolar canal to treat dysesthesia and paresthesia following endodontic treatment of a third molar. Indian J Dent Res. 2014;25(3):413-415. 29. Scarano A, Di Carlo F, Quaranta A, Piattelli A. Injury of the inferior alveolar nerve after overfilling of the root canal with endodontic cement: a case report. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2007;104(1):e56-e59. 30. Scolozzi P, Lombardi T, Jaques B. Successful inferior alveolar nerve decompression for dysesthesia following endodontic treatment: report of 4 cases treated by mandibular sagittal osteotomy. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2004;97(5):625-631. 31. Yatsuhashi T, Nakagawa K, Matsumoto M, et al. Inferior alveolar nerve paresthesia relieved by microscopic endodontic treatment. Bull Tokyo Dent Coll. 2003; 44(4):209-212.

Endodontic practice 43


psychological implications, discomfort/ pain: • Systemic medical management (nortriptyline, pregabalin) • Referral for psychological support • Review For severe symptoms: • Systemic medical management (nortriptyline, pregabalin) • Referral for psychological support • Review • Pain management referral (possible interventional procedures) (Kim, et al., 2013); and Botox (Ngeow, 2010)

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Each article is equivalent to two CE credits. Available only to paid subscribers. Free subscriptions do not qualify for the CE credits. Subscribe and receive up to 16 CE credits for only $129; call 866-579-9496 to subscribe today. To receive credit, complete the 10-question test by circling the correct answer, then either: n Post the completed questionnaire to: Endodontic Practice US CE 15720 N. Greenway-Hayden Loop. #9 Scottsdale, AZ 85260 n Fax to (480) 629-4002.





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Risk assessment of endodontic-related nerve injuries: part 2 RENTON

1. Patients _________ are less likely to recover from nerve injury. a. under the age of 20 b. over the age of 20 c. over the age of 30 d. over the age of 50 2. A key factor in these cases appears to be proximity of the tooth apex to the __________. a. inferior dental canal (IDC) b. perforation c. lingual artery d. intraosseous maxillary canal 3. Assessing the actual position of the __________ can be complex, and the clinician involved in treatment planning must be able to analyze and riskassess radiological investigations and not leave the risk assessment to another clinician. a. IDC b. mental loop c. accessory canals d. all of the above 4. Postoperative root canal treatment views must be arranged on the day of completion of the treatment, and identification of any root canal treatment product in the inferior alveolar nerve (IAN) canal should be reviewed carefully and removed within _____________.

44 Endodontic practice

a. b. c. d.

48 hours 3 days 1 week 2 weeks

5. All radiographic examinations must be justified _________ whereby the benefits to the patient of each exposure must outweigh the risks. a. on a global basis b. on an individual needs basis c. by the insurance company d. by the radiology tech 6. Limited field-of-view CBCT systems can provide images of several teeth from _________ as two periapical radiographs, and they may provide a dose savings over multiple traditional images in complex cases. a. approximately the same radiation dose b. a much higher dose c. a much lower dose d. a safer dose 7. If ________ chemical nerve injury may be presumed. a. calcium hydroxide has been used b. the patient is suffering from neuropathy after the local anesthesia has worn off c. the postoperative radiographs (not CBCT) confirm that there is no radiopaque material in the canal

d. both b and c 8. In some reports, 20% of nerve injuries are delayed in presentation, and the endodontist may need to warn the patient that the onset of ________ up to 3 to 4 days post-endodontic treatment must immediately be reported. a. altered sensation b. pain c. numbness d. all of the above 9. Treatment should be considered within _________ of neuropathy presentation to minimize permanency of nerve injury while maximizing resolution. a. 2 hours b. 6 hours c. 30 hours d. 48 hours 10. To prevent ________, consider creating an apical stop or dentin apical plug; make sure the preparation has taper and hence resistance form; obturating shorter; using cold lateral condensation to gain apical control; do not use resin-base sealers such as AH PlusÂŽ sealer. a. overfill or extrusion b. avoid under-instrumentation c. crown fractures d. taking several types of radiographs

Volume 10 Number 1



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522 at AAE



AAE17 — education, vendors, networking — and all that jazz


ndodontists from all over the United States are traveling to New Orleans to learn about the latest trends in endodontics and all that jazz! From April 26-29 at AAE17, clinicians will explore the business and clinical technologies and techniques that can positively impact the future of your practice. It’s time to learn a new subject, see and touch innovative equipment and materials, and network with other specialty practitioners. At the Ernest N. Morial Convention Center, attendees can earn 28 CE hours listening to educated, talented, and motivational speakers discussing topics including laser-assisted endodontics, tools of retreatment, practice options for new endodontists, endodontic microsurgery, and CBCT systems, plus many other interesting and enlightening subjects. Besides these eye-opening sessions, AAE17 is a great opportunity to discuss possibilities with vendors. In the exhibit hall, you will be able to see products that can make your practice life easier, improve workflow for your team, offer you more treatment options, and provide optimum care to your patients. Endodontic Practice US is excited to showcase some of these powerful and versatile products to whet your appetite and welcome you to these booths. Increased practice efficiency and profitability await your practice, and these companies are awaiting your visit. As they say in New Orleans, “Laissez the bon temps rouler!” (Let the good times roll!) Visit Endodontic Practice US at Booth No. 733

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46 Endodontic practice

Visit Dentsply Sirona Endodontics at Booth No. 119

Volume 10 Number 1

Sonendo® to host lecture, Fun Run at AAE 2017

Genius® Endodontic Motor System

Sonendo®, manufacturer of the GentleWave® System featuring Multisonic Ultracleaning™, is bringing disruptive technology and fun to the AAE New Orleans meeting. The company will sponsor a “To The Point” lecture by Dr. Manish Garala, BDS, MS, and a Diplomate American Board of Endodontics, on Friday, April 28, 12:15-1:15 p.m. in the Exhibit Hall. The company will also host its 4th Annual 5K Fun Run, with a warm-up led by Science Cheerleader Melissa Smithson. Smithson is a former cheerleader for the Tennessee Titans who earned a Neuroscience Degree from Vanderbilt University. The warmup starts at 6 a.m. on Thursday in Hilton Riverside’s Grand Salon A. Sonendo will be in booth No. 649. Stop by for in-booth speakers and demonstrations of the new Anterior/Premolar procedure instrument.

The Genius® Endodontic Motor System gives you both the safety of reciprocation and the efficiency of rotary movement. The Genius endodontic motor, contra-angle, and files are designed to work together as a complete system. The Genius endodontic motor is designed to work optimally with reciprocating and rotary files. It is an adaptable, easy-to-use motor, with various torque settings and smooth, adjustable speeds. The auto-stop settings interrupt movement when a set torque limit is reached to help prevent file separation. The Genius 8:1 contra-angle, designed specifically for the Genius motor, enables endodontic files to reach the required speeds for any procedure. The Genius files have a unique S-shaped cross section that makes them compatible with both reciprocating and rotating movement. We recommend using the Genius files with the Genius endodontic motor, which has pre-programmed settings designed specifically for Genius files.

Visit Sonendo at Booth No. 649

Visit Ultradent at Booth No. 533

CS 8100 3D from Carestream Dental

Easy Endo USA

There’s no doubt that cone beam computed tomography has become the standard of practice in endodontics. Fortunately, the compact CS 8100 3D from Carestream Dental was designed with endodontists in mind. The CS 8100 3D lets doctors collimate to the region of interest with four selectable fields of view, ranging from 4 cm x 4 cm to 8 cm x 9 cm. Plus, the EndoHD mode (5 cm x 5 cm) allows for even the finest details of root and canal morphology to be captured in ultra-high resolution for diagnostic and treatment planning needs. The system helps endodontists make more informed diagnoses on the spot, including apical lesions, root fractures, canal identification, and characterization of internal and external root resorption. Most importantly, the CS 8100 3D’s localized field of view limits radiation to the patient while providing highly detailed images of the region of interest.  In addition to enhanced diagnoses, the stunning high-resolution images also aid in patient education and understanding of a proposed treatment plan — resulting in improved case acceptance. To learn more about Carestream Dental’s portfolio of imaging products and software for endodontic practices, visit us at Booth No. 439 at the AAE Annual Meeting, or call 800-944-6365.

Every so often, a truly disruptive technology emerges that changes how we practice. That technology is here in the form of ProDesign Logic files by Easy Endo USA — the world’s Canal prepared with ProDesign first truly minimally invasive, singleLogic .01/30 & .05/30 instruments file, endodontic instrument system. Prepare the glide path in any manner you wish, use a single rotary ProDesign Logic Shaper, and the canal is prepared in literally seconds. One and done. The parent company of Easy Endo USA, Easy Odontologicos, has been manufacturing products in Brazil for 17 years. Owned by a practicing endodontist, Dr. Henrique Bassi, ProDesign Logic and all of the Easy products are manufactured to the highest global standards. ProDesign Logic is currently the best-selling and fastest-growing nickel-titanium endodontic file system in Brazil, and we are excited to share this technology with America. All Easy Endo USA products are available now at and/or To try Logic and receive a complimentary ticket to our AAE 2017 hospitality reception (being held Thursday evening, April 27), please visit us at the MounceEndo booth. We also welcome you to attend our AAE Logic Hands-on Corporate Workshop on Friday morning, April 28, in Exhibit Hall E.

Visit Carestream Dental at Booth No. 439

Volume 10 Number 1

Visit Easy Endo USA at the MounceEndo Booth No. 555

Endodontic practice 47



AAE PREVIEW MounceEndo AAE 2017 will see MounceEndo launch Easy Endo USA’s disruptive ProDesign Logic nickel-titanium file: the world’s first minimally-invasive, single-file endodontic shaping system. This file must be seen and tried to be believed. It is simply awesome. Visit the MounceEndo Booth No. 555 to try ProDesign Logic and receive a complimentary ticket to our AAE 2017 hospitality reception being held Thursday evening, April 27, at the Convention Center Marriott. We also welcome you to attend our AAE ProDesign Logic Handson Corporate Workshop on Friday morning, April 28, in Exhibit Hall E.

Clinical case treated with a single .05/25 ProDesign Logic File

Visit MounceEndo at Booth No. 555

AAE Save the Crown — No Diamonds Necessary! The TriHawk Talon offer unique hyperbolic design and an impressive rake angle which simplifies delicate procedures, like endo access. The secret to removing any resistant material: Both end-cut and side-cut capabilities facilitate drilling at any angle! Drill coronally, then widen laterally without removing the bur from the access hole. This shape lends itself to cutting semi-precious metals too, as it evacuates material buildup away from the contact point. Meanwhile, most metal cutters are crosscut — the Talon replaces teeth with ultra-sharp blades, which minimize micro fractures and conserve porcelain integrity. See the video at Visit Tri Hawk at Booth No. 931


Brasseler USA XP-3D Shaper

For 25 years, Dr. Assad Mora has been a world leader in pioneering and developing optical and 3D video solutions that bring comfort and efficiency to visualizing dentistry. In 2007, Dr. Mora introduced the MoraVision™3D System, a groundbreaking technological achievement designed to replace the microscope and eliminate dependence on oculars. MoraVision™ enables the dentist to view the operating field, inside an oral cavity, on a 3D video monitor in real time and with accurate depth perception. For the first time, dentists can work with amazing visual acuity and maximum postural comfort, without the usual leaning and craning over the patient. MoraVision™3D brings freedom and precision to the practice of dentistry and unprecedented conceptual clarity to clinical dental education. For more information, visit

The XP-3D Shaper addresses the shortcomings of traditional NiTi instrumentation and ushers in a new biologic standard of care in endodontic instrumentation. The XP-3D Shaper safely, efficiently, and effectively cleans the root canal system three dimensionally while respecting the canal anatomy. As it rotates, the instrument’s orbit expands and contracts to abrade the broad and narrow aspects of the canal equally. This intuitive micro-mechanical debridement allows the practitioner to utilize a single instrument to safely and efficiently clean and enlarge the canal while respecting the original canal morphology. Visit for more information or to schedule a no-obligation in-office demonstration or to reserve our exclusive no-obligation XP-3D Try-Buy Intro Kit.

Visit MoraVision at Booth No. 821

48 Endodontic practice

Visit Brasseler at Booth No. 625

Volume 10 Number 1


Boyd Industries, Inc.

EdgeEndo was founded on a revolutionary idea of creating superior endodontic products for less and passing the cost savings on to our customers. Staying true to that promise not only defies industry wisdom, but also has made EdgeEndo one of the world’s largest rotary NiTi suppliers in 4 short years. Founded by a practicing endodontist, EdgeEndo’s success and future is grounded in the design and development of truly innovative solutions to improve the working endodontist practice while saving them money.

Built to Last. Built for You. Built by Boyd is more than a tagline; it signifies the commitment that everyone at Boyd makes to each and every one of our customers. Best known for the durability and reliability of our awardwinning products, we combine 60 years of design and manufacturing expertise to create personalized products to match your imagination. The Boyd team takes great pride in the craftsmanship of the products we build at our facility. Among our uniquely Boyd products is the new M3100LC chair for endodontists. This chair was specifically designed to meet the functional requirements for endodontists. The chair features a vertical-lift column base, which does not alter the field of view when raising or lowering the patient. It comes standard with easyto-access programmable membrane switch hand controls mounted on both left and right side of the chair back. To learn more, visit us at Boyd Industries is an ISO 13485:2016 certified company.




world’s largest

rotary niti suppliers. FEATURED ON


Visit Boyd Industries at Booth No. 138

The Tip of the Ultrasonic Revolution Our unwavering mission is to turn your ultrasonic unit into the most powerful tool in your practice. We are dedicated to designing, manufacturing, and testing the most innovative and leading-edge ultrasonic inserts to help endodontists perform even the most challenging procedures and deliver the highest quality care to their patients. Dr. Alexandre Capelli is our Research and Development head and is himself a practicing endodontist. He is inspired by real life case issues and takes his field work to the lab to develop our highly sophisticated ultrasonic tips. Additionally, our passion at Helse is to offer this premium technology at a very affordable cost. You will find that our prices are nearly half of many of the top brands. Helse … We have the answer.

American Dental Partners American Dental Partners provides professional support to more than 20 multi-specialty group practices across the country. With our support, they are able to provide their clinical team with the resources necessary for success. Specialists enjoy opportunities for collaboration, a steady patient demand and leadership opportunities, without travelling between multiple locations.

Rewarding Careers We have a variety of opportunities nationwide available for Endodontists. Stop by our booth, or contact Kate Anderson at to learn more.

Visit Helse Ultrasonic at Booth No. 654

Volume 10 Number 1

Visit American Dental Partners at Booth No. 522

Endodontic practice 49




Apical negative pressure irrigation advances endodontic treatment Dr. Brett E. Gilbert answers some questions about advances in irrigation Why do we need more advanced endodontic irrigation? Endodontics has seen vast developments and innovative advances in rotary instruments, ultrasonics, imaging, and the biocompatibility of filling materials over the past 2 decades. However, innovations in technology to irrigate the canals have been more delayed in development. Today, we are finally seeing a surge in advanced irrigation technology. These advances will help us in the ongoing battle of improving upon the classic irrigation technique to accomplish more effective apical cleansing while minimizing the risks of irrigating at the working length of the root canal. The ultimate goal of endodontic treatment is to clean the root canal system. The apical third of this system (the last 3 mm of the root) is the most critical area to clean as this anatomy is a highly complex network of canal space, apical deltas, and fins. A 2006 study by Kim and Kratchman showed that the apical 3 mm of the root canal system contains over 98% of the canal ramifications and 90% of lateral canals as compared to the middle and coronal thirds of the root. Our ability to clean the apical third with mechanical instruments alone is quite limited. After completed rotary instrumentation, Peters, et al. (2001), showed that only 35% of the canal space walls have actually been contacted by the instruments. The rotary instruments we use are effective in creating a pathway within the canal space which allows us to flow our solutions to the end of the canal. We depend on the chemical action Brett E. Gilbert, DDS, graduated from the University of Maryland Dental School in 2001 and completed his postgraduate training in Endodontics from the University of Maryland Dental School in 2003. He is currently a clinical assistant professor in the Department of Endodontics at the University of Illinois at Chicago, College of Dentistry and on staff at Resurrection Medical Center in Chicago. He is a past-president of the Illinois Association of Endodontists. Dr. Gilbert is boardcertified, a Diplomate of the American Board of Endodontics. He lectures nationally and internationally on clinical endodontics. Dr. Gilbert has a full-time private practice limited to endodontics in Niles, Illinois.

50 Endodontic practice

of sodium hypochlorite solution to clean this complex canal space by antibacterial action, tissue dissolution, and biofilm removal capability (Clegg, et al., 2006). The classic technique of positive pressure needle irrigation is the dispensing of solution into the pulp chamber or coronal/middle third of the root canal with a syringe tip. This method does not allow the solutions to reach the full working length of the canal effectively. Historically, we have been ultraconservative with the volume and placement of our sodium hypochlorite solution in an effort to prevent the traumatic incidence of the solution getting past the apex of the root. However, in this effort to reduce or eliminate the incidence of a sodium hypochlorite accident, we have neglected to clean our apical anatomy to a sufficient level. Even in the instance of placement of the irrigating syringe into the apical third of the canal, the presence of the apical vapor lock is problematic. The apical vapor lock is a bubble that forms apically blocking the flow of the solution from reaching the working length of the canal. A study by Chow (1983) describes that for a solution to be mechanically effective, it must create a current force, reach the apex, and carry particles away. These criteria are simply not met with the classic positive pressure irrigation technique.

What is the apical negative pressure technique, and how can it lead the way to more advanced canal cleansing? The advent of the apical negative pressure technique has changed the game of effective apical irrigation. This technique allows for a large volume of sodium hypochlorite and EDTA to be delivered to the full working length of a mechanically prepared root canal. The technique is performed using the Endovac™ Pure. This technology uses negative pressure to pull the irrigating solution from a reservoir in the pulp chamber to the working length by using high-speed suction through small apertures in the cannulas of the unit. Sodium hypochlorite is neutralized

Figure 1

Figure 2: Image courtesy of

quickly in the root canal system by tissue and dentin debris. Apical negative pressure can deliver 188 cycles of fresh solution to the full working length of the canal every 30 seconds, allowing for a constant and fresh exchange of solution (Fanibunda, 1966). Thereby, you are getting fresh delivery and replenishment of full-powered antibacterial and tissuedissolving solution to the most critical part of the root canal system. As the flow of irrigation reaches the full working length of the canal, you simultaneously have a high-powered evacuation of the solution along with debris and particles out of the canal. The Endovac Pure unit delivers a controlled flow of irrigation into the pulp chamber. A macrocannula is placed into the canal to the level of the middle third. The macrocannula has the ability to pull the solution from the pulp chamber down into the canal by a negative pressure force to Volume 10 Number 1


Figure 3

the level of the open aperture at the end of the cannula. Thereby, a negative pressure current force is placed on the solution to flow down the canal and into the high-speed suction opening for evacuation. The larger size of the macrocannula aperture allows for larger pieces of debris to be removed quickly and effectively from the canal. A second cannula, the microcannula, is then placed to full working length in the canal. Again, the high-speed suction at the end of the cannula has a negative pressure pulling force on the fresh solution in the pulp chamber. The irrigant is able to flow down the canal by the negative pressure to reach the level of the high-speed suction apertures at the tip of the microcannula. The solution is then evacuated through the high-velocity suction openings, creating an irrigation flow from crown to apex. As the solution flows down the canal from the pulp chamber to the apical working length and suctioned out, you have a continuous current force of fresh irrigation reaching the apical third. This technique is streamlined and ergonomic as the Endovac Pure unit is operated by one hand through a hand controller, which dispenses the stored solutions (NaOCl and EDTA) by the touch of a button. The two suction cannulas extend right from the disposable apex cartridge into the canals.

How does apical negative pressure irrigation help minimize risk and maximize effectiveness? The inherent lack of risk of this technique is simple. The negative pressure current force on the irrigation solution is driven by the highspeed suction at the tip of the cannulas. If the cannula gets blocked, or the suction force is otherwise disturbed, no solution will Volume 10 Number 1

Figure 4

Today, we are finally seeing a surge in advanced irrigation technology. be present in the apical third of the canal. This is because it relies on the suction force to deliver the solution to the working length of the canal. In a similar way, if the cannula is extended beyond the apex, the negative pressure is no longer created because the cannula will be suctioning outside of the root, and there is no pulling force to pull the solution down into the canal. As clinicians, our highest priority is to assure that our treatments do not harm or pose risk to our patients. Desai and Himel (2010) showed “that the Endovac did not extrude irrigant after deep intracanal delivery and suctioning the irrigant from the chamber to full working length.” The protection of the periapical tissue is fundamentally built into the technique by relying on the high-velocity suctioning force to deliver the flow of solution to the apex. Any interruption of the high-velocity suction will stop the flow of irrigant. Once we have determined that a technique helps protect our patients, we then turn our attention to the efficacy of the technique. Nelson and Baumgartner (2009) showed that there was significantly better cleaning of canals 1 mm from the apex in comparison to needle irrigation (positive pressure) alone. In regards to clinical outcomes, a study by Gondim, et al. (2010), showed that there was less postoperative pain with use of apical negative pressure by Endovac as compared to needle irrigation alone.

What is the clinical impact of advanced apical irrigation? Advances in dental technology continue to increase the efficiency and efficacy of our dental treatments. The delivery of the apical negative pressure irrigation technique with the Endovac Pure is a technique that provides clinicians with the answer to the significant limitations of the classic endodontic irrigation techniques. We are always striving to raise the bar in endodontic success. By irrigating more effectively in the apical third of our root canal systems, we can reach the next level of success in endodontics. EP This information was provided by Kerr Endodontics.

REFERENCES 1. Chow TW. Mechanical effectiveness of root canal irrigation. J Endod. 1983;9(11):475-479. 2. Clegg MS, Vertucci FJ, Walker C, Belanger M, Britto LR. The effect of exposure to irrigant solutions on apical dentin biofilms in vitro. J Endod. 2006;32(5):434-437. 3. Desai P, Himel V. Comparative safety of various intracanal irrigation systems. J Endod. 2009;35(4):545-549. 4. Fanibuna KB. A method of measuring the volume of human dental pulp cavities. Int Endod J.1986;19:194-197. 5. Gondim E, Seltzer FC, Dos Carmo CB, Kim S. postoperative pain after the application of two different irrigation devices in a prospective randomized clinical trial. J Endod. 2010;36(8):1295-1301. 6. Kim S, Kratchman S. Modern endodontic surgery concepts and practice: a review. J Endod. 2006;32(7):601-623. 7. Nielsen BA, Baumgartner JC. Comparison of the EndoVac system to needle irrigation of root canals. J Endod. 2007;33(5):611-615. 8. Peters OA, Schӧnenberger K, Laib A. Effects of four Ni-Ti preparation techniques on root canal geometry assessed by micro computed tomography. Int Endod J. 2001;34(3):221-230.

Endodontic practice 51


Endodontics and implantology: odd couple or opposites attract? Jordan Reiss examines how implants can fit into the endodontic practice


t’s the specialty’s most challenging question that no one wants to answer: Should endodontists be placing implants? There’s a wide range of opinions; just by reading that sentence, you’re probably mentally shouting at the page for or against. Whatever your answer may be, we must face the question head-on by looking at the pros and cons, the facts and the myths, of endodontists placing implants. It’s a new year, and it’s the perfect time to examine how implants could affect your specialty, your practice, and your patients in 2017.

Why implants? Why now? The demand for implants has been steadily increasing for several reasons. First, an increased standard of living has made procedures that were once cost-prohibitive more accessible to more people. Also, the population is aging, yet living longer, and is seeking a solution that provides comfort and better esthetic results than dentures or bridges could. Finally, digital technology such as cone beam computed tomography (CBCT) and 3D imaging software makes placing implants, if not “easier,” certainly more predictable for doctors. With demand on the rise, we’re finding there’s simply not enough supply — i.e., doctors who are specialized in planning and placing implants. Consider periodontists, who for years weren’t trained to place implants but are now doing implant surgeries and placements. In fact, today, nearly every specialty is placing implants in some capacity, even GPs.

The scope of endodontics While the question of which specialty should place implants may be a contested Jordan Reiss is the national sales director of 3D imaging for Carestream Dental and assists practitioners in the transition to various digital technologies. He has spoken at numerous events on different facets of 3D imaging, conducted hands-on events for more than 1,000 clinicians, and has extensive knowledge on the vast landscape of 3D systems available in the market. He holds an MBA from Vanderbilt University.

52 Endodontic practice

Figure 1: Three-dimensional view of maxilla showing DICOM dataset from the CS 8100 3D with an overlay of a digital model from an .STL file from the CS 3600 intraoral scanner

Figure 2: Virtual treatment plan of crown and implant using the Prosthetic-Driven Implant Planning module in Carestream Dental’s CS 3D Imaging software

topic, the path for endodontists to do so has been being quietly paved for years. In 2013, the American Association of Endodontists (AAE) Special Committee on the Scope of Endodontics published a position statement confirming that the “placing of dental implants is within the scope of practice of endodontics.”1 The AAE also clearly references implants in its joint position statement with the American Academy of Oral

and Maxillofacial Radiography (AAOMR)2 on the use of CBCT. As Recommendation 10 states: “Limited field of view CBCT should be considered as the imaging modality of choice for surgical placement of implants.”

Education is key In 2006, the Commission on Dental Accreditation (CODA) endodontic standards was revised to increase endodontists’ Volume 10 Number 1

invites you to attend...

Single-File, Minimally-Invasive Endodontics:

One and Done—It’s Easy A 3-hour, State-of-the-Art, Hands-On, Endodontic Learning Experience presented by Dr. Richard Mounce 4 Learn the latest science in heat treatment of nickel titanium instruments. 4 Discover clinically effective, minimally-invasive, single-file, rotary nickel titanium file utilization, and prevention of iatrogenic events.

4 Practice using state-of-the-art, Easy Endo USA ProDesign Logic instruments. 4 Participate in an interactive learning experience that will prepare you to immediately

Dr. Richard Mounce Dr. Richard Mounce graduated Northwestern Dental School in 1985 and obtained his certificate in Endodontics from Oregon Health Service University in 1991. A practicing endodontist, he is the owner of Disclosure: Dr. Mounce is the North American General Manager for Easy Endo USA, and MounceEndo is a distributor of Easy Endo USA products.

and confidently implement advocated rotary methods into your practice.

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Participants will be asked to bring at least two extracted accessed molar teeth. See our Eventbrite link for details. Material support for this class is provided by Easy Endo USA. For registration information, course details, terms and conditions of attendance, and refund/cancellation policy, please visit http://


Approved PACE Program Provider FAGD/MAGD Credit Approval does not imply acceptance by a state or provincial board of dentistry or AGD endorsement 12/1/2016 to 11/30/2018 Provider ID# 325231 CONTINUING EDUCATION BROUGHT TO YOU BY


MedMark, LLC, Publisher of Endodontic Practice US 15720 N. Greenway Hayden Loop, Suite 9, Scottsdale, AZ 85260 866-579-9496 |

Easy Endo USA 1995 Switch Grass Circle, Ocoee, FL 34761 321-370-4327 | |

This activity has been planned and implemented in accordance with the standards of the Academy of General Dentistry Program Approval for Continuing Education (PACE) through the joint program provider approval of FMC, MedMark, LLC, and Easy Endo USA. FMC is approved for awarding FAGD/MAGD credit.


Figure 3: Three-dimensional view of mandible where the Prosthetic-Driven Implant Planning module has automatically combined an HD 3D color .STL file (from the CS 3600 intraoral scanner) with a CS 8100 3D scan

knowledge of placing endodontic endosseous implants from “familiarity” to “understanding.”1 This understanding can only be gained through specialized training — a must for any doctor before placing implants. In fact, today, some endodontic programs do teach implants. As further evidence that implant placement by endodontists is on the rise, from 2008-2011 there were 37 sessions at AAE continuing education events on dental implants,1 and in 2009, the AAE fall conference topic was “Implants and Endodontics, Treatment Planning and Placement Techniques.”1

Is placing implants right for you? In 2009, a survey sent to 1,500 endodontists in the United States revealed that 57% supported the specialty placing implants.3 However, there are a few important qualifiers here. How will placing implants affect your referral relationships? Contact your referrals to see if they’d be comfortable referring patients to you. Endodontists who have been trained to place implants are more likely to be included in the treatment plan with their referring doctors. How will it affect your bottom line? Being able to offer an additional service to your patients could be a new source of revenue. Most important, by placing implants, are you providing the best care for your patients? Endodontists may be the least biased when it comes to the “who should place implants” debate, as their job is to save teeth; however, sometimes, an implant may be the only alternative. It can be discouraging for a patient (who’s 54 Endodontic practice

already come from another doctor) to hear their endodontist say, “I’m sorry, there’s nothing I can do.” Therefore, the ability to place implants could be a relief to patients who wouldn’t have to be referred out to yet another specialist.

What’s next? If you decide that placing implants is right for you, and assuming you have the appropriate knowledge and training, you’ll need the right tools. When it comes to placing implants today, it’s arguably the standard of practice that a CBCT scan should be taken. Fortunately, most modern endodontists already have experience with CBCT and know firsthand how a scan can aid in diagnosis. Often, the same small FOV, high-resolution low-dose scan — such as one captured by the CS 8100 3D system — taken to evaluate whether a tooth can be saved could also be used to evaluate challenging anatomical variability, pathology and bone quality, and quantity for placement of an implant. Also, Carestream Dental’s CS 3D Imaging software is one of many software

platforms that include an implant library from the top implant manufacturers to streamline virtual implant planning. After virtual implant placement, the 3D image can be used for patient education or for more comprehensive analysis. Carestream Dental also provides a plethora of educational resources to clinicians for learning how to use the virtual implant function and implant library of its software. Only you can determine if placing implants is right for you, your practice, and your patients. However, having some level of knowledge of placing implants is crucially important for endodontists. If a tooth is unable to be saved, the patient who has come to you for your specialty knowledge is going to ask your opinion about next steps. Whether you plan to place implants or not, I sincerely hope you’ll learn more about the role of implants in the endodontic practice. Taking the time to learn more about implant placement may help your referrals, provide salient information to your patients, and ultimately, help you make the decision whether or not to place implants in your practice now or possibly in the future. EP

REFERENCES 1. AAE Special Committee on the Scope of Endodontics. Scope of Endodontics: Dental Implants. American Association of Endodontists. 2013. Accessed January 29, 2017. 2.

The Special Committee to Revise the Joint American Association of Endodontists/American Academy of Oral and Maxillofacial Radiology Position on Cone Beam Computed Tomography. Use of Cone Beam Computed Tomography in Endodontics 2015 Update. American Association of Endodontists/American Academy of Oral and Maxillofacial Radiology. uploadedfiles/clinical_resources/guidelines_and_position_statements/cbctstatement_2015update.pdf. Accessed January 29, 2017.

3. Potter KS, McQuistan MR, Williamson AE, Qian F, Damiano P. Should endodontists place implants? A survey of U.S. endodontists. J Endod. 2009;35(7):966-970.

Volume 10 Number 1

Dr. Garth Hatch discusses the benefits of building trust


n our current political, social, and economic environment, it seems that trust levels in our society are at an all-time low. This has been showcased everywhere from political debates to business boardrooms. However, despite this level of cynicism, businesses with high levels of trust are growing tremendously. Stephen M. R. Covey’s book, The Speed of Trust, discusses seven dividends businesses with high-trust levels receive, which include increased value, accelerated growth, balanced innovation, improved collaboration, stronger partnering, better execution, and heightened loyalty. Here are three groups where high levels of trust are critical to the success of your practice: Patient trust — When patients are referred by their general dentist to see a specialist, they are often nervous about the unknown. When patients call, are they greeted by a friendly, knowledgeable staff member ready to assist and schedule their visit in a timely manner? Does your website portray a modern, professional, and friendly office with up-to-date photos of the doctor and staff? Do your patients fully understand their dental problem and the treatment options available to solve them? Do they feel you are putting their needs ahead of your own self-interests? When treatment is provided, is the patient’s comfort level a top priority? Are follow-up phone calls made to ensure the visit was positive, and the patient is likely to refer you to a friend? If the answer is no to any of the previous questions, improvements should be made to strengthen the trust your patients have in your office.

Referring offices’ trust — No other area in your practice is of higher importance to its long-term success than the relationships and level of trust you have with your referring offices. As H. L. Mencken has said, “It is mutual trust, even more than mutual interest that holds human associations together.” We should clearly communicate what we intend to do, complete what we say we’re going to do in a timely manner, and deliver quality results. When treatment goes less than ideal regardless of the cause, honest communication and a willingness to “make things right” are even more important. Heightened loyalty and increased trust occur when we act with integrity and become problem solvers for both our patients and referring offices.

Employee trust — The level of trust within a practice starts at the top with the doctor/owner. Employees should be treated as co-owners of the practice and incentivized for growth. Involve the team in as many decisions as possible, and encourage collaboration. Employees should receive frequent, on-going training in their specific roles as well as overall training in communication, leadership, and customer service. They should know the owner cares about them not only professionally but also on a personal level. This leads to a high-trust practice culture that is innovative, emotionally healthy, and loyal. As trust levels within your practice grow, so will your practice reputation, staff retention, and bottom line. EP

Garth W. Hatch, DDS, is President and Founder of Dental Specialist Institute, a dental consulting firm committed to helping specialists receive more referrals, profits, and freedom. As an actively practicing endodontist, Dr. Hatch is aware of the challenges specialists face in today’s dental and economic environment. He coaches endodontists and their teams to better leverage their time, space, and efforts to help minimize stress and maximize results. He is a native of Riverside, California, earned a BS in Exercise Physiology from Brigham Young University and his DDS from Indiana University School of Dentistry. Following graduation from dental school, Dr. Hatch entered the US Army Dental Corps and completed a 1-year AEGD residency at Fort Jackson, South Carolina, and later completed an endodontic residency program at Fort Gordon, Georgia. After serving in Germany, he left the military and purchased an endodontic practice in Kennewick, Washington, where he still practices. Despite moving to a competitive dental market, he was able to grow a solo endodontic practice into a successful three-doctor group practice.

Volume 10 Number 1

Endodontic practice 55


Trust — the specialist’s force multiplier


Keep it real with today’s patients


he information technology now on our desks, in our pockets, vehicles, and elsewhere has empowered us all to be uber-informed consumers. And that means an unprecedented value is being placed on options — new, better alternative routes to get us where we really want to be. Could there be a more exciting time for endodontists — specialists in saving teeth — to give both their referral base and patients a technology-based tooth-saving option?

Root Canal Treatment (RCT) is the endodontic standard — even as dental professionals move toward implant-supported crowns. According to a 2013 survey in the Journal of Endodontics, endodontists stated a preference for standard root canal treatment (RCT) when presented with four different clinical scenarios. When compared with endodontists, all other dental specialties expressed a higher preference for implant-supported

crowns, and that preference increased as the tooth required repeated RCT.1

But what would your patients really prefer? A recent Journal of Endodontics survey indicated that 90% of patients2 placed a high value on tooth retention — saving their natural tooth was second only to communication and trust. And when you combine this data with patient survey3 data reflecting a high level of apprehension about RCT, it’s no surprise that people are asking about an alternative to both treatments — one that lets them keep their natural teeth.

Patients are interested in a RCT alternative that lets them keep their real teeth. Sonendo® developed the GentleWave® System, in part, to meet the growing need for options. Via online patient polls,3 Sonendo has been listening to people as they share

“I have been practicing endodontics for 34 years and have tried every advancement on the market. Finally, the GentleWave® System by Sonendo does what I have been trying to do my whole career: thoroughly clean and disinfect the root canal system with minimal instrumentation. I am a believer!” – James A. Smith Jr., DMD, Advanced Endodontics, P.C., Birmingham, Alabama

Figure 1: In a recent online survey3, we asked: “If your dentist told you that you needed a root canal, how would you feel?” 75% were less than positive!

Figure 2: A recent Journal of Endodontics survey indicated that 90% of patients2 placed a high value on tooth retention— saving their natural tooth was second only to communication and trust. 56 Endodontic practice

Figure 3: (left) New anterior/premolar procedure instrument. (right) Molar procedure instrument Volume 10 Number 1

The GentleWave® System: Sonendo’s solution to keeping it real. The GentleWave System uses procedure fluids to deliver unprecedented cleaning and disinfection throughout the root canal system,5,7 helping to preserve the natural tooth and guard against standard RCT failure.6 It’s a higher standard of clean that’s minimally invasive5 — and a procedure that can usually be completed in

one session.6 The broad spectrum acoustic energy and advanced fluid dynamics have the power to reach even the most complex anatomies and remove tissue debris, bacteria, biofilm, and smear layer.5,7 And 2017 marks the introduction of the GentleWave anterior/premolar procedure instrument — enabling endodontists to seamlessly integrate an expanded scope of care to more patients. Multisonic Ultracleaning™ technology works by delivering a broad spectrum of acoustic energy and creating a powerful vortex of procedure fluids that clean the entire root canal system from crown to apex. It is measurably superior to standard treatment, while still preserving more tooth structure.5 In addition, Multisonic Ultracleaning technology can dissolve

organic tissue 7 times faster than standard endodontic systems.8 In addition to detaching and dissolving debris and tissue, the advanced fluid dynamics and chemistry that are essential to Multisonic Ultracleaning give you the power to thoroughly disinfect even complex anatomies.5,7 Smear layer is effectively removed, as is the biofilm that can form in the root canal system within weeks of the initial standard treatment7 — and which can lead to reinfection. Multisonic Ultracleaning is statistically more effective than standard treatment, even in the apical third and areas of anatomical complexities within the root canal system.5 Multisonic Ultracleaning technology is only available with Sonendo’s GentleWave System, and since its introduction, patients and endodontists everywhere have been impressed.

The GentleWave System: Preserving teeth and practice growth. Standard RCT? Implant? It doesn’t have to be an either/or scenario for you, your referrals, or your patients. At Sonendo. com you can see the many ways the GentleWave System gives you dynamic options to address the real concerns of today’s patients and preserve the healthy growth of your practice. Attending AAE? Visit Sonendo booth No. 649 to view the GentleWave System, see and understand the science behind it, and take part in demonstrations. Plus get valuable insight into how it fits into your practice as a source for growth. EP This information was provided by Sonendo®.

REFERENCES 1. Azarpazhooh A, Dao T, Figueiredo R, Krahn M, Friedman S. A survey of dentists’ preferences for the treatment of teeth with apical periodontitis. J Endod. 2013;39(10):1226-1233. 2. Sigurdsson A, Garland RW, Le KT, Woo SM. 12-month Healing Rates after Endodontic Therapy Using the Novel GentleWave System: A Prospective Multicenter Clinical Study. J Endod. 2016;42(7):1040-1048. 3. Facebook poll, September 2016 (Third party) 4. American Association of Endodontists survey, 2016. Dispelling myths of root canals through education: root canals aren’t what they used to be. American Association of Endodontists. press-releases/dispelling-myths-of-root-canals-througheducation.aspx. Accessed February 2, 2017. 5. Azarpazhooh A, Dao T, Ungar WJ, Da Costa J, Figueiredo R, Krahn M, Friedman S. Patients’ values related to treatment options for teeth with apical periodontitis. J Endod. 2016;42(3):365-370. 6. Molina B, Glickman G, Vandrangi P, Khakpour M. evaluation of root canal debridement of human molars using the GentleWave system. J Endod. 2015;41(10):1701-1705. 7. Vandrangi P et al. (2015) Oral Health 72-86 8. Haapasalo M, Wang Z, Shen Y, Curtis A, Patel P, Khakpour M. Tissue dissolution by a novel multisonic ultracleaning system and sodium hypochlorite. J Endod. 2014;40(8):1178-1181.

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their opinions about these standard treatment options. People want to keep their natural teeth, and standard root canal treatments cause most potential patients at least some degree of concern. That’s in keeping with similar findings from the American Association of Endodontists and the Journal of Endodontics.4


MoraVision™ 3D Dr. Assad F. Mora discusses this operating video microscope system that brings a breakthrough to dental technology


he MoraVision™ system’s cuttingedge technology sets a new precedent in today’s dental market (Figure 1). The stereoscopic 3D visualization ushers in a new paradigm in evidence-based clinical decision-making to everyday practice. Imagine sitting up straight comfortably — free to work and perform dental procedures without looking down into the oral cavity or through oculars. Instead, with MoraVision™ dentists can view the operative field with clarity on a large flat panel HD monitor — in real time and in 3D — with accurate depth perception. In addition, MoraVision™3D brings to everyone in a clinical dental education setting the conceptual clarity of seeing the exact magnified operative field, as viewed by the operator, either in real time or from recordings, with depth perception and in the natural state of the three dimensions. This conceptual clarity eliminates any gaps in conceptual understanding, speeding up the learning and teaching processes, and bringing unprecedented efficiency and proficiency to clinical dental education (Figures 2 and 3). At the heart of the MoraVision™ system is an integrated foot switch designed to maximize precision and efficiency by remotely controlling its 16x zoom and fine-focusing functions. MoraVision™3D takes vision ergonomics in dentistry from a posture-dependent fixed line of sight between the eyes and the operative field, either directly or through binocular eyepieces of loupes or microscopes, to a highly variable and posture-independent line

Assad F. Mora, DDS, MSD, is a graduate of Indiana University and a Diplomate of the American Board of Prosthodontics. He is a pioneer in the field of Restorative Microdentistry and has been active in developing and inventing more user-friendly technology for his Microdentistry practice since 1992. Dr. Mora is the inventor of the MORA Interface, which has been adapted to the Zeiss Pico microscope. In 1998, he introduced the use of stereoscopic 3D video technology for viewing the operating field in real time for performing clinical dental procedure. He is a contributor to dental and patent literature, and founder of the Institute of Microdentistry, a research institute dedicated to the development, modification, and implementation of new technologies for the enhancement of the practice of Microdentistry. Dr. Mora resides with his wife, Kathy Patmore (Endodontist), in Santa Barbara, California, where they’ve been maintaining their respective full-time practices in Restorative Microdentistry and Micro Endodontics since 1992.

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Figure 1: The MoraScope™ is a complete video microscope system packing within a 4 inch cube a stereoscopic operating microscope with zoom optics, wonderful illumination, and full HD video cameras, all seamlessly integrated to eliminate the need for oculars and photo/video accessories

Figure 2: Dr. Ryan B. McMahan, Senior Endodontic Resident, University of Michigan, surrounded by new residents

Figure 3: Photo of the 3D monitor displaying a mirror image of tooth No. 2 (shown here in 2D) with completed RCT and GP in canals. Treatment by Dr. Michael P. Thompson, Litchfield Park, Arizona

Figure 4: Dr. Michael P. Thompson, Endodontist, Litchfield Park, Arizona. Apicoectomy on tooth No. 3 with MoraVision™ 3D

of sight divorced from the operator’s face and the binocular eyepieces. With MoraVision™, the line of sight can be gained from any focal point located on an 180˚ hemisphere over the patient’s face (Figure 4). Remarkably, after placing the MoraScope™ over the patient’s torso and aiming it up at the maxillary arch, dentists can clearly see images on the 3D monitor — the occlusal surface of a maxillary second molar, with or without a mirror. This clarity allows dentists to open an access for endodontic treatment (Figure 5) and perform tooth preparations and restorative procedures or harvest a free gingival graft from the palate. Dr. Michael P. Thompson wrote: “Here’s a picture taken this morning, September 1, 2016, while performing an apicoectomy on tooth No. 3 using MoraVision. If I were using a microscope, patients would need to have their head turned to the left as far as possible. But with MoraVision,

Figure 5: Dr. Clara Mora, Santa Barbara, California, cutting the occlusal slot in the process of removing a defective crown on tooth No. 15. Notice the MoraScope™ suspended above the patient’s torso and looking directly into the occlusal surface of the maxillary molars without using a mirror

we all remained comfortable throughout the procedure. My treatment time is noticeably less for surgeries now too. I can’t say enough good things about MoraVision!” EP Volume 10 Number 1

Booth 821

…It’s All You Need.

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Top five dental marketing scams Cory Roletto, MBA, discusses some marketing tactics to avoid


e have all received the letters, seen the emails, and may have even answered a call from a company claiming something that is not true or promising something too good to be true. Over the past 7 years working with dental offices, we have seen our share of less than reputable marketing practices. In this article, we will talk about the top five dental marketing scams. 1. You receive a letter that your domain is expiring and needs to be renewed. This letter may look very official, and many have the word domains in the company name. The form asks you to fill out information about your domain, give your approval to renew the domain, and send payment. The payment request is often $100 or more. With rules established by The Internet Corporation for Assigned Names and Numbers (ICANN), the governing body for domain purchase and transfer, you are unlikely to actually lose control of your domain, but you may not even notice your money didn’t go to pay for domain renewal. If you are in doubt, you can verify the domain registrar by doing a WHOIS lookup on your website domain; most domain registrars have this feature. Here is a link to the WHOIS lookup page on Network Solutions: 2. You receive an email that they have evaluated your website, and it has not been SEOed. These emails are often automated spam emails with wording that makes it sound like they have evaluated your website, but upon closer inspection don’t give any specifics about what they found — because no one actually evaluated your website. They will often make nonsensical statements such as your website is not web

Cory Roletto is partner and co-founder of the dental marketing firm WEO Media, www., where he leads the operations team. He holds a MBA and BS in Chemical Engineering from the University of Washington.

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Avoid marketing scams. Receive your free marketing consultation today: 888-246-6906 2.0 compliant and have a link to test your site, or one of the following blanket statements: a. You have low online presence for many competitive keyword phrases. b. Your social media accounts are unorganized. c. You have many bad back links to your website. d. Your website is not compatible with all mobile devices. e. Your website is being penalized by Google. These types of spam emails have become more sophisticated often using search scrapers to pull some easy-toobtain data about your website that is added to the email to make it appear legitimate. They may also have a graph showing made-up metrics; for example, social media completeness. One other obvious red flag that is the email will not have any information on the company that supposedly evaluated your website, giving just a callback number or a Gmail email to respond. 3. A review directory representative states he/she can get negative reviews removed or make your positive reviews show up more, if you sign up for an advertising package. We have actually had salespeople for a very large, well-known review directory system state this to us and many of our clients. This is always stated over the phone, and they have never put it in writing — because it is flat-out not true. I am sure the directory involved would not condone this type of sales tactic, but

we have seen it so many times, it had to be mentioned. The truth is any reputable directory does not let advertising dollars influence what reviews do or do not show up when searching for a service. 4. They say they have a special relationship with Google. In this instance, the claim is that due to a special relationship, they can do things others cannot, such as getting special pricing on Google payper-click (PPC) campaigns or obtaining a No. 1 ranking on Google search. They may also misuse Google Partner to imply special treatment. Being a Google Partner means that personnel at the company have passed one or more Google certification tests showing they are proficient in some aspect of SEO or PPC. Being a Google Partner is a good thing, but it does not provide any special privilege or advantage other than the fact that the company has taken the time to be certified. 5. They assert that your Google PPC campaign is showing up in Europe because it is using the default settings. This was one of the most outlandish claims we have seen. To start, Google requires the region for the PPC campaign be set as part of the creation of the PPC campaign. Second, there is no way for someone to accurately detect Google PPC campaign settings. Also, if someone guarantees a No. 1 ranking in Google, they can only be referring to Google PPC where the No. 1 ranking can be bought by paying more per click, which is less than optimal. If a salesperson makes any of these claims, run. EP Volume 10 Number 1

Brasseler USA® has unveiled the revolutionary XP-3D™ Shaper endodontic debridement instrument that addresses the shortcomings of traditional NiTi instrumentation and ushers in a new biological standard of care in endodontic practice. The XP-3D Shaper features Brasseler USA’s exclusive MaxWire® Technology that allows the instrument to expand and become more robust when exposed to body temperature. Once an adequate glide path is established, the XP-3D Shaper is able to clean the entire canal without the need for multiple files. The XP-3D Shaper features a small flexible core (#30/.01) that is extremely resistant to cyclic fatigue. The unique serpentine design allows the instrument to gently abrade the inner walls of the root canal without the stress associated with conventional NiTi files. The XP-3D Shaper features a unique freefloating adaptive core that allows the smaller central core of the instrument to move freely and adapt to the canal’s natural anatomy. This dynamic movement also creates enhanced turbulence for improved irrigation. XP-3D Shapers can be used with any endodontic handpiece but for the most advanced experience, use with Brasseler’s EndoSync™ Endodontic Handpiece System, which features the lightest-in-itsclass EndoSync Cordless Micromotor along with the unprecedented accuracy of the EndoSync™ A.I. Apex Locator. The EndoSync syncs with the A.I. to provide real-time apex locator readings as you progress down the canal. For more information, visit

EdgeEndo announces strategic investments EdgeEndo has announced several strategic investments to enhance the company’s commitment to serving endodontists and general practitioners. • The grand opening of a new corporate headquarters and distribution center in Albuquerque, New Mexico. • The selection of Carla Y. Falcon, DMD, MDS, from Rutgers School of Dental Medicine as the 2016 EdgeEndo Fellowship Award recipient. The $250,000 award selection is made by the Foundation for Endodontics. EdgeEndo is funding the award to support Dr. Falcon’s commitment and passion to dental education as full-time endodontic educator. • Attendance at all major trade shows to demonstrate the company’s commitment to continuing education programs while giving dentists the opportunity to experience our new products in person. • The hiring of a new Professional Relations & Clinical Affairs Manager to support collaborations with dental schools and prominent clinicians. For more information, visit, or contact customer service at 855-885-3636.

Kerr™ Endodontics launches OptiDam™ Kerr™ Endodontics has announced the North American launch of OptiDam, a three-dimensional rubber dam unlike any other. OptiDam’s design focuses on four core deliverables: • Efficacy: Its 3D design offers dentists optimal visibility and accessibility to the treatment area. A clean operating area leads to greater success in procedures. • Practicality: Low radiopacity means there is no need to remove the dam during X-rays. Further, its anatomical shape leads to reduced tensioning, meaning dentists don’t need to worry about the dam snapping out of place. • Ease of Use: A distinctive nipple design guides the dental professional during positioning for easer assembly and removal. Its intelligent shape means the saliva ejector can comfortably fit underneath the dam. • Comfort: Specifically shaped to allow patients to breathe freely, the dam also features versatile anterior and posterior versions to adapt to the dental procedure as needed. For more information for the entire Kerr Endodontics family of products, visit, or call 800-KERR123.

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Brasseler USA® introduces the XP-3D™ Shaper


Become an essentialist to find happiness in your success Dr. Joel Small identifies how to reach goals while honoring values


et me begin by saying that happiness and success are not mutually exclusive. I know this seems obvious — perhaps not worth mentioning. However, my experience coaching highly motivated professionals has proven otherwise. I can state with confidence that among highly motivated healthcare professionals, success/happiness imbalance is approaching epidemic proportions. I find that a significant number of my colleagues are struggling to find happiness in spite of their apparent success. The reason, as it turns out, is as multifaceted as the cure. What I have found is that doctors who experience a success/happiness imbalance are actually doing too much. Compounding this problem is their failure to identify what they most value, as well as what is essential. Furthermore, they fail to prioritize and delegate the majority of what they do, and finally, they are unaware of the necessity for establishing boundaries. Let’s explore each of these topics, and how they might contribute to the success/happiness imbalance as well as its cure.

Identify what is most valued I am continually amazed at how many doctors have no sense of what they value. In my opinion, identifying one’s core values and the ability to align these values with actions and behaviors is an absolute necessity in creating both happiness and success. Early in our coaching relationship, each of my clients is asked to conduct an exercise that is specifically designed to identify their personal core values. One of the cornerstones of professional and executive coaching is a

Happiness is the highest level of success. commitment on the part of the client to honor these values in all that they do. I have heard coaching colleagues describe core values as being the guiding principles around which we make all of our personal and professional decisions. To many, core values are “right” or “true.” They are both the sail and rudder that guide our ship to a predetermined destination. When viewing core values from this perspective, it seems self-evident that they are critical elements for both success and happiness. Take the time to define your core values, and then honor them as you follow the path to finding happiness and success.

Joel C. Small, DDS, MBA, ACC, FICD, is a practicing endodontist and the author of Face to Face: A Leadership Guide for Healthcare Professionals and Entrepreneurs. He received his MBA, with an emphasis in healthcare management, from Texas Tech University. He is a graduate of the University of Texas at Dallas postgraduate program in executive coaching and limits his coaching practice to motivated healthcare professionals. He is a nationally recognized speaker on the subjects of leadership and professional development. Dr. Small is available for speaking engagements and for coaching healthcare professionals who wish to experience personal and professional growth while taking their practices to a higher level of productivity. **To receive a free copy of my “Core Values Exercise,” please contact me at I am also available for a complimentary coaching session to discuss your practice-related issues.

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Determine what is essential Greg Mckeown in his bestselling book Essentialism: The Disciplined Pursuit of Less (highly recommended) states that when we fail to purposefully and deliberately choose where to focus our energy and time, other people (bosses, family, patients, staff, etc.) will choose for us, and before long, we will lose sight of everything that is meaningful and important. I can attest to the truth of this statement. By losing sight of what is important and meaningful, we create an imbalance in our success/happiness relationship. One of my clients stated that when she lost sight of what was meaningful, it was as if she were living from a set of values that were not hers. She was financially successful, and yet she felt as if she was working to fulfill someone else’s dream. So how do we determine what is essential? The good news is that essentials are easy to identify. They are those actions and behaviors that only we can complete successfully and that move us closer to our goal while honoring our values. As an Volume 10 Number 1

Prioritize and delegate John Maxwell once wrote, “It is hard to overestimate the unimportance of practically everything.” Once we adopt the philosophy of essentialism, the truth of this statement becomes very clear. Quite simply, we do too many needless things that fail to advance our cause, honor our values, or serve our purpose. Prioritizing and delegating are vital skills that free us from these needless tasks that drain our energy and distort our focus. When we lose energy and focus, we are no longer able to utilize our skills and time to their best and highest use. Take the essential items list you have now created, and prioritize them in order of their relative significance to achieving your goal. Those items that are highly significant will go to the top of the list, while those that are moderately or minimally significant will go to the bottom of the essentials list or drop from the list entirely. You now have a list of perhaps eight to 10 essential tasks that, once completed, have the greatest potential to provide you with both success and happiness. These are the tasks that should demand the majority of you time and focus. Those items that fail to make your essentials list are considered to be nonessential and should be delegated to staff or out sourced. This is not to say that these unessential tasks are insignificant. They may be quite significant. They just don’t have to be done by you. As an example, I have a doctor client and friend who finds himself in the office 5 days per week. His is a very successful clinician, but after 30-plus years of practice, he would like to find a way to cut back to at least 4 days per week in his dental office. He admits to being a poor delegator, so I asked him to keep a journal of his weekly activities for us to review. We both had a good laugh when we realized that he had recently spent a good portion of his Friday afternoon checking the dates on the drugs in his emergency drug kit. When we came across this, I couldn’t help but reply, ”You’ve got to be kidding me!” He laughed as well and knowingly said “You mean someone else can do this?” Enough said. Volume 10 Number 1

Create boundaries Boundaries create clarity with regard to what is or is not an acceptable action or behavior. Consequently they assist us in avoiding nonessential actions that cause us to deviate from our chosen path. For example, in my office, we want our staff to have the freedom and empowerment to make independent decisions regarding our patients’ overall experience in our office. We also want to expedite the decision-making process by making it as simple and clear as possible. My office staff knows that their actions are bound by only two critical considerations: Is their intended action consistent with our practice values and in the best interest of the patient? They find that this degree of clarity and simplicity enables them to effortlessly act within these boundaries

and function expediently without agonizing over the decision-making process. Values dictate the nature of our boundaries, and boundaries are intended to protect our values. In today’s world, our values are challenged on a regular basis, and the most successful and fulfilled doctors are those that make values nonnegotiable. It is their self-imposed boundaries that make this possible. Boundaries are vital to our ability to focus and use our energy efficiently. Boundaries come from a firm sense of commitment to what we value, and they can only exist if we respect ourselves enough to insist upon them. They are the natural progression of the process I have shared: identifying values, determining the essential, prioritizing, and delegating. EP

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exercise, I have my clients keep a journal of their activities throughout the week. At our next coaching session, we review this journal and collaborate on determining which activities meet these criteria. The rest of the activities are categorized and left to deal with as nonessentials.


Minimally invasive endodontics: taking root! Dr. Rich Mounce discusses his guiding philosophy for conserving tooth structure


n dental school, one concept was always considered sacrosanct — conserve tooth structure. In endodontics, we have historically advocated straight-line access and early coronal enlargement to obtain visual and tactile control. In addition, pre-enlargement (opening the coronal third with either Gates Glidden drills or nickel-titanium [NiTi] orifice openers) was considered essential for ease of gaining patency, subsequent shaping, and debris removal. Gates Glidden drills and orifice openers were universally recommended with brushing up and away from the furcation, a motion accentuating dentin removal in the cervical region of the tooth. Posts, in addition to the aforementioned cervical tooth structure removal, are clear risk factors for furcal and vertical root fracture. Slowly, minimally invasive endodontics has begun to take root (no pun intended!) as a guiding treatment philosophy. Minimally invasive endodontics might be thought of as a mindset to conserve tooth structure and use posts only if absolutely necessary. Tooth structure can be preserved by: • Using a contracted (smaller) access cavity (not necessarily straight line) • Avoiding pre-enlargement • Preparing smaller final prepared canal tapers Virtually all endodontists in North America use dental operating microscopes. As a result, we have control over our access size with the caveat that many teeth we treat are already coronally debilitated, and ideal access may not be possible. Conceptually though, keeping access as small as possible, while providing visual and tactile control, is critical. Minimizing post placement will unquestionably prevent fracture. Pre-enlargement was a necessary evil, in large measure because our previous NiTi files are not particularly efficient. We could not take a .06 tapered NiTi file and advance

Treated with ProDesign Logic .01/25 (Glide Path) & .05/25 (Shaper) files

it apically in a one-file technique because no .06 tapered NiTi file could cut efficiently enough to progress apically without preenlargement. As a result, we removed tooth structure through pre-enlargement (often using a brushing motion) in order to allow subsequent files to reach the apex. Unfortunately, this potentiated root fracture due to excessive tooth-structure removal, as mentioned previously. Fortunately, pre-enlargement is a thing of the past, as is the need for larger tapers in endodontic canal preparation. In approximately 90% of all canals, .01/25 tapered controlled-memory ProDesign Logic NiTi Glide Path Files (Easy Endo USA) can prepare the glide path without the use of hand files. Alternatively, clinicians can gain patency with

Rich Mounce, DDS, has lectured and written globally in the specialty. He owns, an endodontic supply company also based in Neskowin, Oregon. He can be reached at,, or by calling 605-791-7000. Disclosure: Dr. Mounce is the General Manager of Easy Endo USA and has a commercial interest in ProDesign Logic Files.

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ProDesign Logic .01/25 file (left) and .05/25 file (right)

a number 10 hand file and follow it with the .01/25 Logic Glide Path File. Once the glide path is prepared, a .05/25 tapered controlled memory ProDesign Logic NiTi Shaper File (Easy Endo USA) can predictably reach the apex in four to five pecks eliminating pre-enlargement and/or a brushing motion. If clinicians want to prepare a larger apical diameter, they can do so using Logic files or any preferred method. The time and cost savings are remarkable because only one file is required after the glide path is prepared. It is a fact, at this time, that no other NiTi system (besides ProDesign Logic) exists in .05 taper that allows a single file minimally invasive preparation of the root canal system allowing canal preparation without pre-enlargement and/or brushing. The resulting prepared canal (.05/25) is more than large enough to be irrigated, activated, and obturated easily and efficiently — all the while conserving tooth structure, the essence of Minimally Invasive Endodontics. I welcome your feedback. EP Volume 10 Number 1



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Endodontic Practice US - Vol 10 No 1 - Spring 2017  
Endodontic Practice US - Vol 10 No 1 - Spring 2017