الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Obtaining acceptable contact areas with adjacent teeth is a significant challenge when placing direct resin composite in class II preparations. The purpose of this study was to evaluate the proximal contact tightness in class II resin composite restorations using different restorative modalities; two types of matrix system (Palodent and Triodent), two types of resin composite (micro-hybrid Vs nano-filled), and one type of ceramic inserts. A total of 80 sets of molars mounted in impression compound mould were used in the study. Occluso-mesial class II cavities were prepared in 80 molar, then teeth were divided into eight groups and restored using different materials and matrix systems. The tightness of the contact area was measured before cavity preparation (control) and after restoration using the universal testing machine, as the maximum frictional force exerted on 0.05 mm thick metal strip upon withdrawal from inter-proximal area in an occlusal direction by cross head speed 20mm/min. The resulted data in Newton were collected and statistically analyzed using two-way ANOVA test followed by Tukey test. Regarding the matrix system, a stronger proximal contact was achieved with Triodent matrix system compared to the Palodent matrix system. Concerning the type of resin composite, the use of nano-filled resin composite resulted in stronger proximal contact compared to use of micro-hybrid, besides, using of ceramic insert resulted in stronger proximal contact area. Finally further short-term and long-term clinical studies are required to confirm the data obtained from the present study.