Influence of bleaching agents on the color change and translucency of resin matrix ceramics

The aim of this study was to investigate the color change, translucency, and whiteness index of three different resin matrix ceramics and a resin composite subjected to different bleaching agents.

Twenty disc-shaped specimens (A2 shaded) for three different resin matrix ceramic brands (Groups Ena, Ulti, and Cera) (totally 60) were prepared using the CAD/CAM technique and 20 nanofiller composite specimens (Group Comp) (A2 shaded) with the same dimensions were prepared as the control group. The color change (∆E₀₀ ), relative translucency parameter (RTP), and whiteness index (WI_D ) of the specimens initial and after different bleaching procedures (home-bleaching and office-bleaching) were calculated using ∆E₀₀ , TP₀₀ , and WI_D formulas. Two-way analysis of variance (ANOVA) and multiple comparison test with Bonferroni correction (α = .05) at the significance level of P < .05 were performed for the comparisons of ∆E₀₀ values. The RTP and WI_D values were evaluated by using repeated measures ANOVA and multiple-comparison test with Bonferroni corrections (α = .05) at the significance level of P < .05.

Bleaching procedure and material type were found to be significant regardless of bleaching type for RTP and WI_D values. Material type has a significant effect on the ∆E₀₀ values. The highest color change values were determined in Group Comp (P < .05).

Bleaching procedures significantly affected the RTP values of Groups Ulti and Cera (P < .05). ∆E₀₀ values for the resin matrix ceramics after the bleaching procedures were below the clinically acceptable values, regardless of the bleaching agent.

Optically, materials such as resin matrix ceramics have properties different from not only enamel and dentin but also among themselves. The possible effect of bleaching agents on these materials should be considered carefully while choosing the restorative material.