Special tests

What Special Tests does the Dentist do?

  • Palpation

This is where the dentist feels the mucosa overlying the roots to see if any swelling is present. If a tooth is particularly infected or an abscess has formed, then there is likely to be some level of inflammation in the bone surrounding the tooth that the dentist can feel. In this case, we know the nerve in the tooth has died.

  • Percussion 

This is where the dentist taps gently on your tooth with either a finger or the handle of one of the instruments in order to try and identify the tooth causing the problems. If the nerve has become necrotic (died) and infection is around the end of one of the teeth, then one particular tooth is likely to stand out and be painful compared to the others. The dentist will often test the other side too for comparative purposes. We record each of the teeth tested in our notes and assign it a grade depending on your response. TTP (tender to percussion) + means a little more tender than normal, ++, definitely more tender and +++ if it is extremely tender.

  • Mobility 

If there is inflammation in the periodontal ligament surrounding the tooth or an acute apical abscess has formed, this can raise the tooth slightly in the socket and make it may appear slightly loose. It is important to rule out other possible causes of increased mobility such as periodontal disease. More information on the grading of mobility can be found in the assessment of gum disease.

  • Vitality testing

Sometimes called ‘pulp testing’, are tests done to try and determine the state of the nerve inside the tooth. On a very basic level we are trying to determine if it is alive or dead, but these tests aren’t totally accurate and really only give us an indication- a piece of the jigsaw- as we try to discover which tooth or teeth are causing the problem.

We have three main ways in which we do this:

(i) Electric current- the dentist may hold a little probe against the tooth that sends out a small electric current of increasing strength to try and produce a response from the nerve. Don’t worry it doesn’t hurt- you won’t get an electric shock but you may feel a little tingle inside the tooth if it is alive. The technique for this is pretty sensitive and we sometimes get misleading results, as it is possible to stimulate nerves endings in the surrounding gum.

(ii) Cold- various methods exist for applying cold to a tooth. The most common is ‘ethyl chloride’- a spray that is put on a cotton wool pledget and applied to the tooth, but ice sticks and other methods are also used. Whilst the spray is very cold (in the region of -30c), it is not like putting ice cream on your front teeth and the moment you feel anything, the dentist will withdraw and I suggest you just pop your tongue on the tooth to warm it up. If a tooth is already sensitive then this test would not be necessary and simply using air from the 3 in 1 syringe would be good to identify the problem tooth.

(iii) Heat- if the tooth is painful to heat, the dentist may wish to confirm this by using a bit of Vaseline to make sure it doesn’t stick and a heated GP point-( this is the filling material used in root canals).

  • X-rays

These form such an important part of a dentists’ armoury, that we have dedicated a whole section to the different types of dental X-rays that may be needed. The extra information that X-rays provide is crucial to working out what is wrong, what needs to be done and is an integral part of the examination procedure.

The X-ray (s) that the dentist will take depend on the problem they suspect. Listed below are the main views that may be needed and in what circumstances:

Bitewing X-ray– If you have symptoms of reversible pulpitis, this X-ray taken on the problem side, will help to look for any dental caries in-between your teeth.

Peri-apical X-ray– If you are having symptoms of irreversible pulpitis, it is important we are able to see if there are any changes around the tips of the roots and this won’t show on the bite-wing above, so we take this view instead. We would also take a peri-apical X-ray if any symptom or test suggests a problem in the tissues around the root such as pain on biting or tapping (percussion), if the tooth is loose, or if an abscess or swelling is present.

OPG This X-ray is useful when there is range of problems and symptoms, or multiple broken teeth which could be causing the problem as it shows all the teeth and the entire jaw. It is good for identifying problems with wisdom teeth,or the jaw, or simply as a place to start when the history of the problem is particularly confusing.

Note. Sometimes more than one view will be necessary.