This in vitro study aimed to evaluate the micro-leakage at the occlusal and cervical margins in class II cavities in permanent molars restored with a low shrink silorane resin composite (Filtek P90) applied with or without etching and two methacrylate-based composite resins (valux plus and Amelogen® plus). Two standardised class II box cavities were prepared in proximal surfaces of 60 sound non-fluorotic permanent molars which were divided into three groups of 20 each according to the type of composite. Group I: silorane-based composite (Filtek P90) in the mesial cavity and methacrylate-based microhybrid composite (Adper single bond 2/valux plus) in the distal cavity, Group II: silorane-based composite in the mesial cavity and silorane-based composite with previous etching in the distal cavity, and Group III: silorane-based composite in the mesial cavity and methacrylate-based micro-hybrid composite (PQ1 /Amelogen plus) in the distal cavity. The samples underwent an artificial aging with thermocycling. Root apices were sealed with transparent orthodontic resin and coated with transparent varnish except 1 mm around the restoration. The specimens were immersed in 1% methylene blue solution at room temperature for 48 hour. The samples were sectioned longitudinally in the mesiodistal direction and evaluated under a stereomicroscope at 20X. Scoring was done according to the depth of methylene blue penetration into the cavities. Statistical analysis of the data was performed using SPSS 17.0 software. Silorane-based composite resin showed less micro-leakage than the methacrylate-based composites. Etching improved the sealing ability of silorane restorations. Silorane-based composite preceded by etching had less micro-leakage among the other materials used in this in vitro study. Keywords: Silorane, methacrylate based composite, sealing, micro-leakage, class II cavity
Effect of Different Filler Loading on Fracture Resistance of CAD/CAM Resin Composite restoration in Premolar Teeth: An In vitro Study