Evaluation of a pulse oximeter and customized probe for pulp vitality testing

Current routine methods for assessment of pulp vitality rely on stimulation of A-delta nerve fibers and give no direct indication of blood flow within the pulp. Recent papers have suggested that pulse oximeters may be used to diagnose pulp vitality by detection of blood flow. In this study, an optimized pulse oximeter probe for teeth was designed, built and tested using the Biox 3740 Oximeter (Ohmeda, Louisville, CO). Following preliminary in vitro tests, the probe was tested clinically. Pulse waveforms from maxillary and mandibular anterior teeth were noted. Simultaneous readings from the subjects' finger were used as controls. Pulse wave readings from the teeth were found to be synchronous with the finger probe, but not consistently. It was easier to maintain continuous readings from mandibular incisors than from maxillary incisors. The average percentage synchronization with the pulse was 28.95% for maxillary incisors and 50.28% for mandibular incisors. This difference was significant (p = 0.05). The overall accuracy of the commercial instrument was disappointing, and in its present form it was not considered to have clinical value.