Pulpal responses to cooling tooth temperatures.

This investigation measured pulpal blood flow and sensitivity to electrical stimulation as tooth temperatures were lowered. Dark rubber dams were placed on test teeth before placement of the cooling device in an attempt to shield gingival microcirculation. Laser Doppler flowmetry was used to measure pulp blood flow, whereas sensory thresholds were recorded simultaneously using an electric pulp tester. As tooth temperatures were lowered, the teeth became less responsive. Pulp blood flow also slowed, but did not completely stop. Results indicated that sensory thresholds were altered, and in some subjects, abolished, without total cessation of pulpal blood flow.