Page 1


Dr Paul Moore. BDS Gate Dental Clinic. Dock Road Galway Ireland 091 547 592 A general practitioners view and accumulation of advice from those who know better. Together with our own experience in general practice on how to diagnose a tooth’s vital status.

Vitality testing is just an aid to your diagnosis. The actual values recorded will vary depending on which tester you are using, the patient themselves and the health of the pulp. Consequently you need to test a group of teeth and also the contra-lateral tooth to find out what the 'normal' values should be for a particular tooth. Even then the results can be misleading - for example a multi-rooted tooth may give a perfectly 'normal' response, yet one of the roots could contain necrotic tissue. As for the differences between a reversible and an irreversible pulpitis, this is never cut and dried. Clinically it can be a very grey area. The difference between a reversible and an irreversible pulpitis is a clinical decision. You are basically trying to assess when a pulp will remain vital, and when it won't. Diagnostically this is not always easy as the symptoms won't always fit nicely into your diagnostic algorithms. Consequently pulp vitality testing should only be used as part of your diagnostic tool-kit. First, and most importantly, listen carefully to what the patient tells you about the pain history, character, response to stimuli. Look at the tooth - is it carious, does it have a restoration already, is there an obvious (or not so obvious) fracture. Look at the rest of the mouth - what is the general dental health like. Any signs of infection - sinus, erythema, swelling - is the tooth TTP? Take a radiograph - any signs of apical changes, but remember it takes a while for an abscess to actually show any radiographic changes.

You need to build up the whole picture prior to using your special tests. You will get conflicting results from different tests, but your job as the clinician is to weigh up all the evidence and give a diagnosis. Here is a sequence of twelve steps helps you correctly diagnose most teeth. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11 12.

History Radiography – Intra-oral / Three dimensional Percussion-Tapping. Palpation Cold Test Heat Test Electric Pulp Test Trans-illumination Bite Stick Magnification Selective Anesthesia Mobility

1. History. Listen to the Patient.

Listen to everything the patient wants to say. Not only will you get useful information, but you are letting the patient know that you have time and concern for him or her.  Depending upon the information the patient supplies, you can often shorten the diagnostic procedure. Good questions to ask are: • What do you think the problem is? • What happens when you take hot or cold drinks or food? • Does it hurt when you bite on it? • When does it start hurting? • How long does the pain last when it starts • How bad is the pain on a score of 1 – 10 ? • Does anything relieve it? • How long has this been going on?

2. Radiography. Intra-oral periapical x-rays from varied angles are an essential. It may show a periapical or periodontal area, decay, resorption, deep fillings, fracture, or thickened PDL. No diagnosis should be made without them. If there is a sinus present, run a gp point to the source of the sinus and image that in place. Case One:

This “OPG view” from the cat scan shows the UR5 obturation complete but symptoms still present from the UL – note the periapical lesion showing on the UL6 and an endodontic peroiapical lesion discovered on the UR4

Axials of the UR6 comfirm lesions on the UR6 buccal and palatal roots and the UL4 palatal and buccal roots – these were not visible on the periapicals.

The Completed root canal on the UL6

Case Two:

Root canal obturation Porcelain post and Core and Cerec E max crown on the LL5 and inlays on the LL6 LL7 show the radioluscency of the restorations and the radio-opaque of the Variolink junction between restoration and remaining tooth structure. This facilitates long term monitoring of the restorations.

Three Dimensional Radiography Within the last twenty years, digital imaging techniques have been replacing conventional film based radiography. The interpretation of two-dimensional images is confounded by distortion, inherent magnification and overlap of anatomical structures. The change from analogue to digital imaging, cheaper cone beam x-ray tubes and computers along with high quality flat panel detectors have made CBVT a reality for the modern dental surgery. Medical computed tomography differs from CBVT in that it uses a fan-shaped rather than a cone-shaped beam and captures portions or slices of anatomy as the source and receptor move along the long axis of the section of anatomy being examined. The radiation dose equivalent for medical CT of the maxilla and the mandible is 2100 microsievert, whereas for CBVT it is between 30 and 400 microsievert. Digital panoramic radiography range from 5 to 15 microsievert, whereas a full mouth series ranges from 33 to 84 microsievert depending on different variables. Potential endodontic applications of CBVT include analysis of invasive cervical resorption, external and internal root resorption, assessment of non-endodontic pathology, diagnosis of canal morphology and endodontic pathosis, as well as planning for endodontic microsurgery. The proximal and axial views are of particular interest, because they are not generally seen with conventional periapical radiography. In addition to generating 2-D slices, 3-D reconstruction enables further assessment of areas of interest.

3. Percussion-Tapping. Percussion-tapping with the mirror handle on the tooth in a vertical direction often allows you to identify the tooth that has inflammation in the ligament and, consequently, hurts the most to tapping.  If two teeth together hurt to tapping, immobilize one with your finger while tapping the other and then reverse the process. Often you will find that one hurts significantly more than the other and will be the more suspicious of the two. We always suggest tapping a tooth that we think is normal first to allow the patient to compare to. Percussion is NOT a test for vitality and may be caused by occlusion, trauma, fractured roots, sinusitis, periodontal disease and extension of the pulpal disease onto the periodontal ligament. 4. Palpation. Press into the sulcus above the apex of the root or roots. Often the endodontically involved tooth will be more tender than the others if the inflammation has extended into the periapical region, and palpating in this way will produce a greater sensation. You should also be able to detect any swellings or fistulas that may be present. Palpate the lingual of teeth with the same goals in mind and sublingually / cervically feel for swollen nodes indicative of possible infection.

5. Cold Test. Easiest is Endofrost ( -50 degrees) or this is simply done with cylindrically shaped ice sticks. (Make them by placing water in empty anesthetic cartridges and adding a piece of dental floss that extends to the bottom of the cartridge and has a handle on the open end Keep them in the freezer and withdraw the frozen cylinder when needed.) A good site of cold application is generally the buccal surface as close to the “CEJ� as possible. You can cover the gingival with block out gel to reduce confusion with sensation from the temperature change on the gums. If a metal crown restoration is on the tooth, attempt to apply the ice on the lingual metal collar, an area where the cold travels most easily.  If a tooth has irreversible pulpitis it will either give a prolonged response, possibly after some delay, or no response. Transient pain (less than ten seconds) after the application and removal of ice is normal. No response may mean the tooth is endodontically involved, especially if all other teeth respond to cold.  If sharp transient pain occurs that is greater than the pain felt in surrounding teeth, check to see if the bite is high. Root canal is probably not needed and the bite adjustment will eliminate the hyper response to cold.

6. Heat Test. Using

a ball of hot gutta percha on the tip of a plastic instrument, place the gutta percha onto the tooth the same way you would the ice. Wait approximately 15 seconds between teeth to assess the possibility of a delayed, but, prolonged response.  Compare the results from other tested teeth. If one tooth gives a prolonged response, whether immediate or delayed, it is a most suspicious candidate for endodontics. If the pain is immediately relieved by cold, the tooth probably needs root canal.

7. Electric Pulp Test (EPT). This test should be used when the hot and cold tests fail to give clear information on the state of vitality of the tooth. Again, the information supplied by the electric pulp test must be weighed against the response from other teeth. the fact that a tooth does not respond to the EPT has little meaning if all the other teeth also do not respond, unless of course this is the only tooth with a well-defined area at the apex or is quite tender to percussion. Electric pulp tester uses electric excitation to stimulate “A� delta fibres within the pulp. A positive response to EPT does not provide any information about the health or integrity of the pulp it simply indicates that there are vital sensory fibres present within the pulp.

Often, irreversible inflamed pulp is responsive to EPT because it still contains vital and functional nerve fibres that can produce a toothache.

EPT provides only a responsive or non-responsive result that correlates, in many cases, with vital or non vital pulp status. Therefore attempting to interpret the numerical values produced by EPT is not predictable. EPT does not provide any information on the vascular supply of the pulp which is the true determinant of pulp vitality. Teeth that temporarily or permanently lose their sensory function will be non responsive to EPT however they will have intact vasculature. To achieve consistent result with EPT one must follow a standard procedure. Dry the tooth to be tested with gauze and isolate with cotton roll. Cover the tip of the electrode with Vaseline. If the tooth has a metal proximal restoration squeeze rubber dam between the contacts to prevent conduction to the neighbouring teeth. Explain to the patient about the possible unpleasant sensation. The patient can share the holding of the handle and can pull it off instantly if required. This acts like a switch. Then the electrode is placed on the dry enamel of the tooth being tested on the middle 3rd of the facial surface of the crown. Current flow should be increased slowly to allow the patient time to respond before the attendant tingling sensation becomes painful. Each tooth should be tested two or three times and an average should be recorded. For multi rooted teeth may need to be tested by placing the electrode on more than one location

8. Bite Sticks. Use

bite sticks to check for incipient fractures that are causing pain to a tooth when under function. By having a patient bite on each cusp and laterally move the lower jaw, each cusp is subjected to lateral stresses. If a section of the tooth under a cusp has an incipient fracture it will often hurt when pressure is applied.  If a fracture does exist, the tooth may not need endodontic therapy if the fracture does not extend into the pulp. The pain generally disappears if the fractured portion of the tooth can be removed and restored eg with a bonded restoration or cuspal coverage.

9. Trans-illumination. Trans-illumination

often confirms the portion of the tooth that has the fracture. By placing the transillumination light source on the lingual side of the tooth and turning out the chairside light source, fractures may be picked up as a dark horizontal line against a light background. Trans-illumination can sometimes differentiate between vital and non-vital teeth with the non-vital appearing duller than the surrounding ones when the light source is applied.

10. Magnification. It is excellent for picking up fractures simply because you can look at teeth magnified up to 30 X with excellent illumination using loupes / microscopes.

11. Selective Anesthesia. It

should be applied with an intra-ligamental gun. If specific anesthesia to one tooth makes all pain disappear for a short time and the effect is repeatable, the anesthetised tooth is probably endodontically involved.

12. Mobility. Tooth mobility indicates the integrity of the attachment apparatus. Using two mouth mirrors to apply alternating lateral forces in a facial lingual direction to observe the degree of mobility of the tooth. Degree of depression can be tested by pressing the tooth into the socket and noting degree of vertical movement. • 1st degree mobility is barely perceptible. • 2nd degree mobility is no more than 1 mm horizontal movement. • 3rd degree is is greater than 1 mm of horizontal or vertical depression. The pressure exerted by the purulent exudates of an acute periradicular abcess may cause considerable mobility but it resolves quickly once drainage for the exudate is established

13. Test Cavity. I f you believe that a non-vital tooth is causing symptoms, but cannot confirm non-vitality with assuredness, a test cavity without anesthesia may allow entry into the pulp without any pain, thus confirming your suspicions.

Discussion Even after using all these tests we may find at times that we are still not confident in making a definitive diagnosis. It’s worth noting some pain that appears to be dental in origin is not. Problems involving the temperomadibular joint, sinuses and the trigeminal nerve often mimic endodontic pain, but, will not disappear after treatment. If you suspect non-dental causes, refer the patient to the appropriate specialist (medical or dental) and seek a second opinion. Good diagnosis comes from using as many of the above tools as are necessary to confirm as solidly as possible your opinion on what should be done. My experience is that patients truly appreciate the time you take to confirm what should be done.  This is especially true when a patient comes in with a strong feeling that one specific tooth is the source of the problem, but your diagnosis says that it is another and after treatment you are right. If it turns out that you are wrong at least you have performed the tests and screening and recorded the observations. I hope this will be rare, but the exception is always there to catch you out. Good luck and thank you for reading. Dr Paul Moore BDS. Gate Clinic Dock Road Galway. 091 547592. Personal email

When is a Tooth Vital  
When is a Tooth Vital  

A general practitioners experience in root canal diagnosis.