Pulp responses to precise thermal stimuli in dentin-sensitive teeth

The purpose of this study was to determine whether pulpal responses to cold temperatures applied to enamel, using a method that precisely controls the intensity of the cold stimulus or measures the response time, could distinguish dentinsensitive teeth from nonsensitive teeth. Eighteen human subjects were stimulated with cold temperatures decreasing in 5°C intervals (and with tetrafluoroethane) on exposed root and enamel of a dentin-sensitive tooth and enamel of a contralateral nonsensitive tooth. Pain threshold, intensity of pain, time to pain onset, and duration of pain at baseline, 4 h, 8 h, and 1 week were measured. Responses to enamel stimulation of sensitive teeth compared with the nonsensitive teeth usually were highly correlated and not significantly different. The exception was a longer duration of pain in the dentin-sensitive teeth (4.62 ± 0.47 s) compared with nonsensitive teeth (2.92 ± 0.49 s; p = 0.016) after enamel stimulation with tetrafluoroethane. Longitudinal studies are necessary to determine whether these slight increases in pain duration indicate an increased probability of pulpal degeneration or need for dentin protection.