Physiologic Evaluation of Dental-Pulp Testing Methods

¹ School of Dentistry, University of Washington, Seattle, Washington

The vitalometer was found to be the most effective and positive stimulus for checking the vitality of the pulp tissue of a tooth by means of physical and thermal tests. Credence is given the theory that the pulp tissue is stimulated electrically rather than the periodontal membrane by a study of the graph in Figure 2. A non-vital tooth responded with a 2.5-3.0 µmho pen-marker deflection, as compared with an 8.5-10.0 µmho deflection for the vital teeth. Cold air and the explorer did not provide sufficient pulp reaction for an adequate pulp test unless an open lesion was present or the cementum of the patient was especially sensitive to stimuli in general. Thermal stimuli such as ice, ethyl chloride, and heated gutta percha were of value only in cases where the teeth in general were sensitive to temperature changes. The latter two statements are based on physiologic measurements that might equally be attributed to the stimulation of the periodontal tissue rather than pulpal tissue. In the use of thermal stimuli, such as ice cones, the sensory reception progressed slowly and then reached the pain threshold with a sharp, prolonged pain sensation. This situation may result in apprehension of further testing, as does a strong stimulus, such as is provided by the vitalometer when improperly used.

This experiment led to the observation that the patient will volunteer a reaction to a pulp test, although physiologically he has not received a stimulus of sufficient strength to determine the vitality of the tooth. This is of particular interest in diagnostic problems, as the patient may not understand the true significance of the test and a non-vital pulp or diseased pulp may be recorded as normal.