Discoloration of various types of resin cements under laminate veneers

Abstract

Introduction: Because of existing variety of resin cements in the world and their claims of unchangeable color after cure and lack of amine compounds and releasing of fluoride, it is necessary to evaluate the color stability of light cure and resin cements and compare the quality of color consistency. Materials and Methods: This experimental study was performed on 30 circular porcelain veneers of IPS Impress ll (e-max) type A1 with a thickness of 0.5 and diameter of 8 mm in 3 subgroups (n = 10). The veneers were mounted on 8mm zirconia dyes (similar to veneers) and thickness of 1mm to simulate a tooth in A1 dye made by CAD / CAM. The veneers were cemented after polishing and pasting the non-cemented surface with two types of light cure resin cements from different brands of Variolink veneer Ivoclar vivadent and RelyX veneer 3M and one type of dual cure Panavia V5 Kurarey cement. In order to investigate the effect of aging on the color stability of the cement, the discoloration of the specimens was measured by spectrophotometer. The color stability was evaluated three times at times T0 (after cementing), T1 (one month after cementing), and T2 (three months after cementing). The specimens were exposed to ultraviolet light in two phases as (T0-T1) (T1-T2) for 150 h at each phase. They were immersed in artificial saliva at 37 ° C. Results: In the T0-T1 interval (one month after cementation), the highest amount of discoloration occurred in Variolink Veneer Ivoclar vivadent at 2.3 and the lowest in Panavia V5 at 1.31. In the T0-T2 interval (late in the third month), the highest discoloration was reported for the Variolink Veneer Ivoclar vivadent at 3.8 and the lowest for the Panavia V5 at 1.4. But in the T1-T2 interval compared to the T0-T1 interval, the situation changed and the lowest discoloration occurred in RelyX 3M with 1.04 and the highest discoloration in Variolink Ivoclar vivadent with 3.7. There was no statistically significant difference between the mean discoloration in the RelyX 3M group and that in the Panavia v5 group (P-value>0.05). There was a significant difference between the mean discoloration in the Variolink group and the mean in both groups of RelyX 3M and Panavia v5 and the mean discoloration in the Variolink group was higher than the mean discoloration in both groups ; and There was a significant difference between the mean discoloration in the Variolink group in secound Aging time. (P-value<0.05). Conclusion: Over time, light cure and dual cure cements of Variolink, Panavia and RelyX have discolored, which is clinically unacceptable at the end of the third month (T2) in Variolink cement.