effect of three wavelengths of diode laser on the efficacy of bleaching of stained teeth

Objectives: light irradiation and heat have been used to accelerate the process of tooth bleaching. this study aimed to assess the efficacy of conventional bleaching compared to laserbleaching using three different wavelengths of diode lasers.materials and methods: in this invitro experimental study, 40 extracted human central incisors were immersed in a coloring solution made of tea, coffee, and cola for 21 days. the l*, a*, and b* color parameters were measured before and after the immersion using spectrophotometry. the teeth were then randomly divided into four groups (n=10) as follows: group 1: 810nm diode laser + biolase laser white 20, group 2: 940nm diode laser + biolase laser white 20, group 3: 980nm diode laser + biolase laser white 20, and group 4: conventional bleaching with opalescence boost without laser irradiation. oneway analysis of variance (anova) was used to assess the effect of laser type and bleaching technique on color parameters.results: the 940nm (∆e=28.5896) and 810nm laser groups (∆e=21.2382) showed the highest and the lowest bleaching efficacy, respectively; however, the groups were not significantly different in terms of bleaching efficacy (p>0.05).conclusion: laserbleaching with 810, 940 and 980nm wavelengths of diode laser has an efficacy similar to that of conventional bleaching but in a shorter period. no difference was noted between different laser wavelengths in terms of bleaching efficacy.