بررسي آزمايشگاهي ريزنشت1 اينله هاي كامپازيتي با استفاده از دو نوع سمان چسبنده

Evaluation of microlikage in composite in lays luted with two cement

Objective: Polymerization shrinkage still is a composite disadvantage. In composite inlays because that indirect restoration fill the most of the cavity, so little composite remains which releases shrinkage. In addition, the shrinkage of composite material depends on their composition and viscosity. The aim of this study was to evaluate micro-leakage in direct composite inlays which cemented with low and high viscosity cement. Materials and Methods: Fifty mesially boxes (2 x 3 x3 mm) with 6o diversion prepared with Surveyor appliance. Composite inlays were prepared and were post-cured in 100oC water for 7 minutes to complete their polymerization. Surface preparation was accomplished with 37% phosphoric acid on both inlays and dental surfaces and Exite bonding and Silane coupling agent were used. Teeth were divided randomly into 2 groups: 1- cemented with high viscosity cement (F2-Dual), and 2- cemented with low viscosity cement (variolink II). Both were prepared manually. All the restorations were polished, thermocycled and dye-penetrated by incubation 24 h in 0.2% Fuchsin. Finally the teeth were sectioned buccolingually and evaluated by stereo-microscope (40x). The data were analyzed with Mann-Whitney test. Results: Only 2 inlays did not show any micro-leakage. Microleakage mean value for high viscosity cement group was 20.60 and for low viscosity cement group was 26.95 (P<0.05). Conclusion: According to this study high viscosity cement has less microleakage than law viscosity cement. Although using low viscosity cement is easier because of better flow property, the quality of high viscosity cement is better.