Thermal tests, electric pulp test and use of modified pulse oximeter for assessment of pulpal status of permanent mature teeth: an in vivo study

The assessment of pulp vitality is a crucial diagnostic procedure in the practice of dentistry, and for treating traumatized teeth. Assessment of the teeth vitality is complicated by the fact that the dental pulp is enclosed within calcified tissues. Traditionally, the dentist has related on testing methods designed to reproduce symptoms associated with pulpal pathosis. The methods include thermal stimulation , electrical stimulation, anaesthetic testing or direct dentin stimulation . These modalities fall short of the ideal pulp tests on several criteria. All these testing methods have the potential to produce an unpleasant and occasionally painful sensation, and eventually obtaining inaccurate results by a drip of ice on to adjacent teeth or gingival tissues, or when electric current applied to the tooth surface is conducted in the periodontal ligament, thus stimulating periodontal nerve fibers. False negative responses may also occur in the cases of calcific metamorphosis, in the teeth with immature root formation, or subsequent to an impact injury . All these are subjective tests that depend upon patients perceived response to a stimulus as well as the interpretation of that response. Another problem with these traditional pulp testing methods is that they only indirectly monitor pulp vitality by measuring the neural responses and not circulation. An ideal pulp test must be -simple, objective, standard, reproducible, reliable, painless and low-con. These traditional tests are pulp sensitivity tests. However, the main limitations of these tests are that they assess the neural response of pulp while the main indicator of pulp vitality is its blood supply. Moreover, efficacy of these tests depends on the presence of adequate number of mature neurons in the pulp tissue.

 A direct measure of the blood circulation of pulp is the only real measure of the pulp vitality. The pulse oximeter is a non-invasive oxygen saturation monitoring device widely use in medical practice for recording blood O2 saturation levels during the administration of general anesthesia. Recently, few studies were done using pulse oximetry to detect the 02 saturation of the pulp. Based on these pioneering studies, the present original work was undertaken to compare the clinical effectiveness of the pulse oximeter over the conventional techniques of cold test and electric pulp tester.

 But no such pulse oximeter is available in market for dental use only and these conventional pulse oximeters has some drawbacks like they measured the vitality of teeth only accessible areas of oral cavity and operator cannot hold the light emitting and light absorbing probe proper and steadily at the surface of tooth. To overcome these limitations probe holder was modified by using 3D printer machine. The material was PGA- poly glycolic acid polymer. Modified pulse oximeter probe holder was allowed for holding the probe parallel to each other, firmly and securely.