Barry Musikant

1. Take a good history. 
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?
• Does it hurt to hot or cold? 
• Does it hurt when you’re chewing?
• When does it start hurting?
• How bad is the pain?
• Does anything relieve it?
• How long has it been hurting?

3. Employ 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.

4. Employ palpation.
Press into the fold 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 

5. Apply the cold test.
This is simply done with cylindrically shaped ice sticks. Make them by placing water in empty anesthetic carpules and adding a piece of dental floss that extends to the bottom of the carpule and has a handle on the open end of the carpule. 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 cemento-enamel junction as possible. 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. Apply the 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. Apply the 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.

8. Use bite sticks.
Use bit 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 endodontics if the fracture does not extend into the pulp. The pain generally disappears if the fractured portion of the tooth can be cleaved off.

9. Employ transillumination.
Transillumination 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 amber background. Transillumination 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. Use the binocular microscope.
It is excellent for picking up incipient fractures simply because you can look at teeth magnified up to 30 X with excellent illumination.

11. Apply selective anesthesia.
It should be applied with an intraligamentary gun. If specific anesthesia to one tooth makes all pain disappear for a short time and the effect is repeatable, the anesthetized tooth is probably endodontically involved.

12. Drill a test cavity.
If 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. 

Even after using all these tests we may find at times that we are still not confident in making a definitive diagnosis. Realize that 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) unless you are knowledgeable in these areas yourself.
    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, that is the subject of another article!