Surface and pulpal temperature comparison of tooth whitening using lasers and curing lights

Abstract

Chemical action of bleaching agents applied to tooth surface is accelerated by increase in temperature. This in vitro study measured the temperature rises on the surface and in the pulp of teeth during whitening using a diode laser, a plasma arc curing (PAC) light and conventional curing lights. Extracted, non-carious single-rooted teeth were exposed to PAC light and laser at times ranging from 10 to 60 seconds and energy ranges of 2 W, 4 W, and 6 W, and to low-intensity curing lights from 1 to 4 minutes. Maximum temperature rises were analyzed for both pulpal and surface temperature. Diode laser exposures at 2 W for all times and at 4 watts for 10 seconds and PAC light exposures at 10 seconds all produced acceptably safe pulpal rises equivalent to conventional light-curing exposures. Exposures at these settings also attained surface temperature rises that were significantly higher than those using conventional light-curing. The diode laser demonstrated bleaching results equivalent to the PAC light, and both were achieved in significantly less times than conventional light- curing.