Effect of resin cement type on the final color of high translucent zirconia before and after thermocycling: an in vitro study.

Abstract

Aim: Advancements in dental cements were made to enhance bonding to zirconia. However, their effect on the color stability of the restoration is still unclear. The purpose of this study was to compare the effect of amine-free MDP-containing dual-cured self-adhesive resin cement versus light-cured resin cement on the final color of monolithic high translucent zirconia before and after thermocycling. Subjects and methods: Twenty high translucent zirconia discs, shade A2 (0.5 mm thickness, 10 mm diameter) were obtained, air abraded and randomly divided in two groups (n=10) according to the cement type used; Group CH: cemented by choice 2 (light-cured resin cement; control), Group ZC: cemented by ZR-Cem (amine-free MDP-containing dual-cured self-adhesive resin cement; intervention). Specimens were cemented to PMMA discs and subjected to thermocycling. Color was assessed after cementation and after thermocycling using laboratory spectrophotometer. After testing for normality, collected data revealed parametric distribution and were expressed as mean and standard deviation. Data were statistically analyzed at a level of significance (P ≤ 0.05). Results: After cementation, color change was significantly lower in Group ZC (ΔE= 2) than in Group CH (ΔE= 3.8). However, after thermocycling, it was significantly higher in Group ZC (ΔE= 3.63) than Group CH (ΔE= 2.47), being within the clinically accepted range. Conclusion: Resin cement type and aging affect the final color of thin high translucent zirconia restorations. Light-cured resin cement has more resistance to artificial aging compared to amine-free MDP-containing dual-cured resin cement.