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.