Non‐invasive recording of blood flow in human dental pulp

Laser Doppler flowmetry was applied to human teeth to study whether blood How in the pulp can be recorded. In sensitive, intact incisors the level of the output signal Ironi the flowmeter was clearly distinguishable from that obtained in adjacent nonsensitive or pulpeetomized teeth. Heart beat synchronous oscillations, which were present in the recording signal from normal teeth, were absent in nonvital teeth. Local injection of lidocaine (20 mg/ml) with adrenaline (12.5 μg/ml) caused a pronounced and long‐lasting reduction of the flowmetric values in healthy teeth. The oscillations were also reduced in amplitude. Repeated recordings showed good reproducibility. Thus, changes in blood (low may be assessed in a tooth by tin's non‐invasive method. The instrument is a promising tool in the clinical evaluation of pulp vitality following traumatic injuries.