Information of circulation from soft tissue and dental pulp by means of pulsatile reflected light: Further development of optical pulp vitalometry

Objectives. To show experimentally and clinically that information of blood circulation patterns can be obtained through dentin and enamel by means of reflected light. Study design. Several different experimental techniques were developed in vitro leading up to in vivo tests. Results. Pulsatile information of back-scattered light at 560 nm was obtained in an experiment in which a thread with white and red sections was pulled through the empty pulp cavum. The pulsatile information of back-scattered light of 560 nm wavelength was detected from a forefinger of a volunteer through dental hard tissue plates. There was a difference in the radiant flux of back-scattered light in extracted teeth filled with various materials. Photoplethysmograms obtained from the vital pulp of a 24-year-old woman were analyzed with Fast Fourier Transformation (FFT). The analyzed data showed a dominant amplitude of heart rate near 1 Hz. Conclusions. Tests indicated that reliable information of circulation can be obtained from the dental pulp chamber by means of the optical reflection method. This could serve as a model for a new type of pulp vitalometer.