Evaluation of Color Changes of Different Resin Cements in Feldspathic Ceramic Crowns After Accelerated Aging: an in Vitro Research

Abstract

Aims: To evaluate the color changes that occur after accelerated aging in feldspathic ceramic crowns cemented with three different dual-cured resin cements. Materials and Methods: For each of the A2-colored RelyX U200, G-CEM LinkForce, and Panavia V5 cement groups, 45 dies from A2-colored zirconia blocks and 45 crowns from CEREC blocks were prepared. Color measurements after 24 h of cementation (T1) and after cycles of aging of 1750 (T2), 3500 (T3), and 7000 (T4) in the thermal cycle device were made using SpectroShade Micro device. The coordinates of the color were used L*, a*, and b* as base and the color change was calculated with Delta E-00 in determining the color. One-way analysis of variance test was used to compare the times in terms of Delta L*, Delta a*, and Delta b* values. Results: It was found that Delta L* value decreased significantly in period of the T2, T3, and T4 times compared to T1 in all groups (P<.05), whereas the change between period of T2, T3, and T4 times was not significant (P>.05). The Delta a* value increased significantly in the period of T3 and T4 times compared to T1 in the only G-CEM LinkForce group, whereas the Delta b* value increased significantly in the period of T4 time compared to T1 in the only Panavia V5 group. The changes in Delta E-00 values, which were observed in all period of times, were found to be between 0.43 and 1.04, 0.43 and 1.43, and 0.40 and 0.97 in RelyX U200, G-CEM LinkForce, and Panavia V5 groups, respectively. Conclusion: After accelerated aging, it was found that the color of all cements became darker and the G-CEM LinkForce group turned red and the Panavia V5 group turned yellow. However, it was found that the color changes that occurred were within clinically acceptable visible levels.