Sense and Sensibility: How to Track down the Source of Tooth Pain





By Rebecca Stone September 10, 2019

Teeth have a way of getting your attention when something is amiss. But the source of pain is not always easy to track down. The pain may be referred and the offending tooth not easily located. And interlinked conditions can be a challenge for clinicians to untangle.

For endodontic issues, such as pulpitis, X-rays may not reveal the problem. This is because only hard tissues are radiographically visible. Pulp is a soft tissue. Therefore, other diagnostic measures must be employed in addition to radiography.1

Diagnostic Tests

Clinical testing may involve palpation, percussion, or bite pressure tests. Another measure, thermal testing, has a long track record of reliability. Cold testing can be done using commercial refrigerants or homemade ice sticks.

Heat can also be an effective diagnostic measure. It can be applied in the form of warmed compounds, or through the use of methods that include commercial heating devices, spinning prophy cups or even hot water.2

Electric Pulp Testers

Other kinds of pulp tests can evaluate the vascular supply of a tooth. These involve the use of laser Doppler flowmetery or pulse oximetry.3

Electric pulp testers (EPT) are a common step on the diagnostic ladder. They can help determine whether a tooth is capable of feeling, and can record the degree of sensation. These diagnostic devices feature probes, that, when placed on a tooth, along with a conductant such as toothpaste, emit mild electrical currents.2

Starting at a low level, the intensity is increased until the patient feels what may register as a tingling sensation. A tooth whose pulp is diseased may exhibit a stronger or quicker reaction to EPT than a normal tooth would. If the pulp is necrotic, there will not be any sensitivity. But clinicians should be aware that electric pulp testers can’t determine pulp health. They can only register sensation or no sensation. And false positives are a possibility.

Lack of feeling is not necessarily indicative of lack of vitality. In cases of trauma, pulps that are still vital are frequently rendered temporarily insensible. For that reason, measures that depend on neural response, such as EPT, are not really considered “vitality testers.”2

Process of Elimination

The goal, of course, is to reproduce the pain described by the patient to identify the offending tooth. It’s often best to start by using adjacent teeth as controls to see how a patient reacts to stimuli placed on a normal versus a diseased tooth. Such a strategy can also help patients relax, allowing clinicians to get more reliable results.2

The characteristics of pain in response to stimuli can also aid diagnoses. For instance, painful response to a stimulus that goes away once the stimulus is removed, may be indicative of a fracture, exposed dentin as a result of gingival recession, or caries. Lingering pain may signal an endodontic problem.

Many sensibility tests can benefit from the use of isolation of the tooth in question via a system such as Isolite. This can be especially helpful in obtaining reliable results from thermal testing, as neighboring teeth are shielded from stimuli. And due to Isolite’s continuous suction, bathing a tooth in cold or hot water is easily accomplished. In addition, when EPT is used, tooth isolation is important in keeping enamel dry and confining electrical impulses to the target tooth.3

While these kinds of tests don’t necessarily determine the condition of a tooth and the cause of pain, they can reveal which tooth is the source of the pain and give the clinician an inkling as to what may be going on. And that’s a good place to start.1,2

REFERENCES

  1. Berdan Y. Five misconceptions in endodontics. Decisions in Dentistry. 2017;3(8):13–16,18.
  2. Stone R. Dental detectives. Mentor.2017;8(4):22-24,26.
  3. Gopikrishna V, Pradeep G, Venkateshbabu N. Assessment of pulp vitality: a review. Int J Paediatr Dent. 2009;19:3–15.