effect of conventional in-office bleaching and laser assisted bleaching at two different wavelengths on color stability of glass-ionomers

Background and aim: bleaching can improve the color of restorative materials and resolve problems related to discoloration or color mismatch. this study evaluated the effect of in-office bleaching method in conjunction with two different laser wavelengths on color change of two types of glass-ionomer restorative materials (light-cure and self-cure). materials and methods: in this experimental study, thirty samples were fabricated of fuji ix, and fuji ii lc glass-ionomer restorative material and specimens of each glass- ionomer were divided into three subgroups (n=10) receiving the following treatments:1. laser assisted in-office bleaching with opalescence boost® along with 980nm diode laser; 2. laser assisted in-office bleaching with opalescence boost® along with 810nm diode laser; 3. conventional in-office bleaching with opalescence boost ®. the color of all specimens was evaluated before and after bleaching with spectro shade. data were analyzed using two-way anova followed by tukey’s hsd test. results: total color change (δe) was significantly different before and after bleaching in all groups (p<0.001). in fuji ix group, there was no significant difference in δe between 980nm diode laser and control group (p=0.14). however, the control and 980 nm groups were significantly different with the 810nm diode laser group (p<0.001). no significant difference was found in δe of fuji ii lc groups (p=0.082). conclusion: bleaching with or without laser results in a significant color change in light-cure and self-cure glass-ionomers.