We have developed noninvasive plethysmographic techniques for determining the status of the blood circulation in the dental pulp. By -detecting minute changes in the intensity of light scattered by the tooth during systole, the vitality of a tooth can be established unequivocally. Preliminary results indicate that the oxygen saturation (SO2) of blood in the pulp can be estimated from intensities scattered from the tooth at three wavelengths. Theoretical results and preliminary data obtained from both in vitro and in vivo experiments suggest that the use of these plethysmographic methods for routine assessment of tooth vitality in the clinic is feasible.
