An In Vitro Study: The effect of refrigerating Silorane and Methacrylate-based composites on microleakage occurrence in Class II restorations

The aims of this study were to evaluate the microleakage in the Class II Cavities Restored with methacrylate resin composite (Tetric Ceram HB) or silorane resin composite (P90 Filtek) that had been stored in different situations and temperatures. Materials and Methods: thirty six intact human upper first premolars were employed. Two Class II cavities with specific dimensions had prepared on each tooth mesially and distally. Teeth were Restored by Methacrylate Resin (HB IVOCLAR), Silorane Resin (P90), Under three different conditions: Group (A): application of composite and Adhesive System at room temperature (24°C), Group (B): application of composite and Adhesive System, immediately after removal from refrigerator temperature (4°C), Group (C): application of composite and Adhesive System, 30 minutes after removal from the refrigerator at room temperature (24°C).Results: This study observed a statistically significant increase in microleakage when applying each of methacrylate composite (HB IVOCLAR) and silorane composite (P90) immediately after removal from refrigerator temperature (4°C) Compared when applied at room temperature (24°C) and when applied 30 minutes after removing from refrigerator temperature, no significant differences were found between silorane composite (P90) and Methacrylate composite (Tetric HB) in microleakage when comparing the two types of resin in the three ways used in storing both resins.

Clinical Comparative study between modified metal matrix and gingival retraction cords for microleakage in class V restorations

This study aims to in vivo evaluate the direct microleakage, in class V composite restoration after isolation using the modified metal matrix or gingival retraction cord impregnated with Adrenaline. Materials and Methods: the research sample consisted of 15 patients; each patient has two premolars at least prepared to be extracted for Orthodontic reasons in the same jaw. This sample divided into two groups according to the place, the right premolars group and the left premolars group, whether was upper or lower. Class V cavity was prepared with a specific dimensions on the buccal surface only, then isolated teeth of the first set by modified metal matrix while isolated teeth of the second set by a gingival retraction cord impregnated with Adrenaline. Teeth restored by composite resin, and then was extracted in the same meeting and studied the microleakage winning directly during restoration. .Results: there was statistical difference between the modified metal matrix and the gingival retraction cord impregnated with Adrenaline. Because modified metal matrix had achieved the lowest leakage rate.