The effect of preheating silorane-based composite resin on gap formation of class V restorations

Abstract

Most of the complications in composite restorations especially posterior direct restorations are due to polymerization shrinkage and the efforts to offset this effect has been the aim of many researches. The aim of the present study was to survey the effect of preheating silorane based resin composite on gap formation of Cl V restorations. Materials and methods: standard Cl V preparations were made on buccal surface of 46 sound bovine teeth then randomly divided into 2 groups: group1 usingsilorane adhesive system and filling the preparation with silorane base composite ( Filtek silorane, 3M, ESPE, USA) at room temperature. Group 2 using silorane adhesive system and filling the preparation with silorane based samples were sectioned and studied with stereo microscope. Gaps were measured at 3 external; middle and internal points and the mean values were listed. The data was analyzed with two-way ANOVA test at a significance level of =0.05. Results: the mean value of marginal gap in non preheated group (12.74 3.83) was significantly more than the mean value in preheated group (7.65 2.07)(P<0.001). However the difference between occlusal and gingival margins was not statistically significant(P=0.61). Conclusion: preheating silorane-based composites before photo polymerization, decreases marginal gap formation in class V restorations