Resin cements effect on the final color of novel monolithic CAD/CAM restorations

Abstract

BACKGROUND: This study investigated the effect of resin cement shade on the final color of computer aided design/computer aided manufacture (CAD/CAM) restorations. METHODS: Thirty CAD/CAM block specimens were fabricated (14x12x1.5 mm) by cutting blocks (Vita Mark II [VM], Vita Enamic [VE], and Lava Ultimate [LU]). Forty cement specimens were prepared (14x12x0.2 mm) using resin cement (RelyX Ultimate Tr, A(1), A(3)O, Bl). Color measurements of CAD/CAM specimens were made without (control) and with each/shade of resin cement (test) with a spectrophotometer. Color differences (Delta E-00) between the control and test groups were calculated and analyzed by 2-way ANOVA and subsequent pairwise testing. Comparisons were performed by using Tukey's multiple comparison tests (alpha=0.05). RESULTS: Both cement shade and interaction between cement shade CAD/CAM block type parameters were significant on color differences (P<0.05). A(3)O cement resulted in a clinically unacceptable color differences (Delta E-00>2.25) for each tested CAD/CAM blocks. Delta E-00 values of VM_A(1) and VE_A(1) groups were also higher than clinically unacceptable level (Delta E-00>2.25). Delta E-00 value of VE_Tr was lower than visually perceptible level (Delta E-00 <= 1.30). There was no statistically significant difference found between the Delta E-00 values of CAD/CAM blocks in the same shade of cement groups (P>0.05). CONCLUSIONS: Tested CAD/CAM blocks were similarly affected by the cement shade and thus may have similar optical features.