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.