اثر جهت نوردهی بر ریزنشت دو نوع کامپازیت مایکروفیلد و هایبرید

Introduction: One of the most important factors affecting the marginal seal of composite restorations is polymerization shrinkage. The aim of this study was to evaluate the micro leakage of two resin composites cured with two light directions. Methods: In this experimental study, forty similar class III preparations were prepared in 40 human anterior teeth. The teeth were randomly divided in two groups according to the resin composite used for filling the cavities (Microfilled composite: Heliomolar or hybrid composite: Spectrum). Etch group was further divided in two subgroups according to the light direction buccal and lingual. All the cavities were filled with the composites and cured for 40 seconds. The teeth were then thermocycled for 500 cycles between 5-55°c and covered with nail polish except for 1mm around cavity margins and immersed in 1% methylene blue for 12 hours. The teeth were sectioned and the dye penetration scores were recorded using stereo microscope. Data was analyzed using non parametric Mann Whitney test. Results: No significant difference was observed between the composite resins (p>0.05) or the light directions used for curing the composite resins (p>0.05). Conclusion: Directions of the light does not have any effect on the micro leakage of hybrid or micro filled composites in class III cavities.