Optical properties and surface structure comparison of tooth whitening using four laser system and chemical action agents

摘要

The purpose of the study is to evaluate the effect of various laser techniques for bleaching teeth in office vital whitening. Hydrogen peroxide (30 % concentration) and carbamide peroxide (10 % solution) were used for chemical activation of bleaching process. Extracted non-carious upper central incisors were exposed to laser radiation. Four different laser systems (Nd:YAG laser SHG, wavelength 0.53 μm, CTE:YAG laser, wavelength 2.7 μm, Nd:YAG laser, wavelength 1.06 μm, and alexandrite laser, wavelength 0.75 μm) were applied to accelerate the speed of the process. The end of chemical exposition was verified by the change of bleaching agent color. The color change was determined by stereomicroscope (Nikon SMZ 2T, Japan), the quality of surface structure was checked by scanning electron microscope Jeol (Japan). The speed of bleaching ranged from 630 s (chemical methods only) to 250-340 s (chemicals + alexandrite laser radiation). The Alexandrite laser application was considered an elective process to decrease the time of bleaching without modifying the surface.