Laboratorial comparison of color stability of resin composites after rebonding with two different adhesive materials

Discoloration of resin composites is considered to be the major factor in esthetic restoration failures. The aim of this study was to evaluate the color stability of resin composites after rebonding with two different adhesive materials. Forty five composite disc samples were divided into three groups [n=15]. The surface of specimens was finished by polishing disc and rubber. In group 1, any additional phase was not performed. In group 2, composite discs were etched by%37 orthophosphoric acid, then Margin- bond was used for rebonding. In group 3, the etching procedure was in the same manner used for group 2, but Permaseal was used after etching. After the first phase of spectrophotometric measurement, the specimens were dipped in coffee mix for 3 weeks for aging the specimens. Then the second phase of spectrophotometric evaluation was performed. Collected data was analyzed using one-way ANOVA test followed by Tukey test. P<0.05 was considered as the level of significance. The mean total color difference [Delta E] observed in groups 1 to 3 were 1.4 +/- 0.34, 5.24 +/- 1.51, and 7.44 +/- 1.34, respectively. Statistical significant differences were shown between the groups [P<0.001]. Rebonding with adhesive materials used in this study did not increase the color stability of composite restorations