Pulpal blood flow in vital and nonvital young permanent teeth measured by transmitted-light photoplethysmography: a pilot study.

PURPOSE The purpose of this study was to record transmitted-light photoplethysmography (TLP) from young permanent teeth and examine its applicability to pulp vitality assessment. METHODS Twenty-six healthy and 7 nonvital upper maxillary incisors in 17 children (ages 7 years, 3 months to 14 years, 8 months) were examined. Recordings of TLP were made with and without opaque black rubber dam application in a darkened room. Finger photoplethysmography (FPP) of the participants was simultaneously recorded. RESULTS (1) Pulse waves synchronous with FPP were recorded from all healthy teeth, whereas no pulse signals were recognized in nonvital teeth. (2) The signal amplitude in the TLP was not significantly affected by the opaque dam application. (3) In the healthy teeth, there was a significantly negative correlation between the TLP pulse amplitude and the age of the subjects. CONCLUSIONS TLP can detect pulpal blood flow in young permanent teeth. This technique is considered to be applicable in the assessment of pulp vitality.