Comparison of repair shear bond strength of a silorane-based composite resin as a result of aging and surface treatment with Er,Cr

Abstract

Successful repair of composite resins requires a proper interfacial bond between the old and the new composite resins. The aim of the present study was to evaluate the effect of surface treatment with CO2, Nd: YAG and Er, Cr: YSGG lasers on repair shear strength of aged silorane-based composite resin. Materials and methods: seventy-six cylindrical samples of a silorane-based composite resin (Filtek Silorane) were prepared and stored in water 37c for two months then randomly divided into 4 groups as follows: group 1: without surface treatment; groups 2, 3 and 4 with surface preparations using Er, Cr: YSGG, Nd: YAG, CO2, and lasers, respectively. The topographic effects of each of the surface preparation methods were evaluated under an electron microscope. Also another group (group 5) was assigned in order to measure cohesive strength. After placing the new layer of composite resin (Filtek Silorane), on treated surface of samples shear bond strength values were measured and data was analyzed with one-way ANOVA and a post hoc Tukey test at a significance level of =0.05. Resualt: The highest and lowest repair shear strength values were recorded in groups 2 and 1, respectively. However In laser treated groups, there were no statistically significant differences in shear strength values between group 1, 3 and 4.the microscopic evaluation of composites showed different degrees of ablation and surface roughness in laser treated groups. Conclusion: surface preparation of aged silorane-based composite resins with Er,Cr:YSGG ,Co2 and Nd:YAG couldn't be effective in establishment of repair bond strength between aged and repaired composite resins.