Implants now chapter 3 digital technology and implant dentistry

Chapter 3 Digital technology and implant dentistry - Aws Alani

Digital technology has modified and improved the delivery of clinical dentistry particularly in the past decade or so. From digital photography to the utilisation of cone beam computed tomography (CBCT) - also referred to as C-arm CT, cone beam volume CT, or flat panel CT - to guide implant placement, these developments have improved patients understanding of the planning and experience during the procedures. Improvements in visualisation of the prospective surgical site have been one of the main areas of treatment enhancement. The ability to see vital structures and adjacent teeth when planning implant placement decreases complications and increases the scope of achieving an acceptable prosthetic result.

Stent fabrication for CBCT scanning Accurate records are a prerequisite for provision of a radiographic stent for implant placement. Depending on the number and position of the edentate spaces requiring replacement facebow records and mounted study casts maybe required.

Where edentate spaces are associated with anterior guidance or there is a planned increase in occlusal vertical dimension then there is a definitive need for full records.

In contrast in a patient who has a solitary edentate space with a stable occlusal relationship then stent fabrication can be provided without further records. Where stents need to be fabricated for implants in the aesthetic zone a wax-up and intraoral mock up prior to stent construction would be wise.

Once records are taken, the construction of a stent requires close liaison with the laboratory technician as to what is required. If the prosthetic replacement required seems straightforward the technician can wax up the crown into the site, duplicate the model and then provide a vacuum formed splint which needs to be filled with a radiopaque material. The material of choice is barium sulphate which can be incorporated into acrylic and then placed into the edentate area. To provide the practitioner with appreciation of the bone volume within the site and the proposed prosthetic unit the technician or the dentist can drill a hole through the occlusal portion of the guide, the void from which can be seen on the subsequent scan. This can provide an idea for the clinician on the scope for a screw retained restoration.

Once fabricated the dentist may consider the need for a try-in appointment to ensure seating of the guide and stability intra-orally for the duration of the imaging.

16

3Shape TRIOS 3

More than just a digital impression system Digital Impressions

Shade Measurement

Intra-oral Camera

Restoration driven implant planning and guide design

Implant impressions for single and multiple units

TRIOS3 CART

TRIOS3 by 3Shape, the worlds leading provider of CAD/CAM solutions for laboratories offers fast and flexible powder-free scanning for the widest range of indications. Seamless integration with the full suite of 3shape software offers you a system that will revolutionise the way you practice, complementing your clinical skills and enhancing the patient experience.

TRIOS3 POD

UK: (020) 8816 7840 Ireland: (01) 808 4446

info@esmdigitalsolutions.com www.esmdigitalsolutions.com

17

Authorized Reseller

Interpretation of the Scan Once the scan is completed analysis can be achieved through the use of bespoke implant planning software or generic CBCT imaging programs. The CBCT scan can be visualised through a number of different planes. Axial, vertical, horizontal and transverse views provide information on the bone envelope that would not be available with traditional 2-dimensional imaging. From both axial and transverse views the assessment of the long axis of the implant and the available bone for implantation can be achieved. Indeed, where the bone envelope available is adequate but at an angle remote from the long axis of the prosthetic tooth an abutment retained restoration would have to be considered. Where there is a minor lack of bone, more likely on the buccal aspect, the need for bone grafting with particulate matter can be planned for. In cases where a severe lack of bone is present in the horizontal direction then block grafting would need to be considered.

Once the bone envelope is assessed planning for the size and shape of the implant can begin. Choice considerations need to include accommodation of at least 1.5mm space between the implant and the adjacent tooth root whilst also providing adequate depth of the implant fixture head. If the implant is placed at too shallow a depth, a consideration where too long an implant is placed, then an abrupt emergence can result in suboptimal aesthetics.

Utilisation of the radiopaque guide at surgical placement At the time of surgery the scan needs to be accessible and be able to be referred to during surgery. Placement of the stent can now provide a surgical guide triangulating information between the patient, the scan and the associated laboratory work.

18

Digital impressions The emerging field in digital dentistry is impression taking without the need for a ‘wet’ impression. Other positive aspects include the ability to retake impressions almost instantly, the ability to record soft tissue as well as hard tissues, the recording of the shade, the recording of the occlusal relationship and the ability to digitally design every aspect of the restoration. Aesthetic characterisation of the restoration may seem to be the most pertinent aspect of this process. The detail of the functional aspect of the restoration can also be designed. Contact areas, cuspal inclines and the emergence of the implant restoration can be planned.

Once the impression is taken it can be saved and utilised again in the future if required for record or for refurbishment of the restoration without the need to physically store models or casts.

Due to the relatively new nature of these new technologies problems are only likely to become apparent with time but it seems as though the current generation of scanning workflows have ironed out previous problems.

Overall, the emergence of new technologies and the refinements and developments of existing systems is helping to improve efficiency of implant procedures as well as patient experience and of course ultimately patient care and satisfaction.

19