Effects of KTP laser irradiation, diode laser, and LED on tooth bleaching: a comparative study.

Objective: This in vitro study examines the whitening efficacy of a light-emitting diode (LED), a diode laser, and a KTP laser irradiation in dental bleaching by analyzing the change in color achieved from the treatment, the temperature increase induced in the pulpal cavity, as well as enamel microhardness measurement after treatment. Background Data: Bleaching techniques achieved significant advances with the use of coherent or incoherent radiation sources to activate the bleaching agents. Methods: A hydrogen peroxide bleaching agent, Hi-Lite, was stimulated with an LED, a 980-nm diode laser at 0.8 W, or a 532-nm KTP laser at 1.0 W for 30 sec on 64 extracted human incisors. During irradiation, the temperature in the pulpal cavity was monitored. The color change was evaluated using the CIE L∗a∗b∗ color space measurement system, and Vikers enamel microhardness was tested after treatment. Results: A mean total color difference value (ΔE∗) greater than 5.0 was obtained in each group. KTP-laser–induced bleach...