Objective: The purpose of this study is to compare the clinical performance and related properties of three esthetic restorative materials nano-filled composite (Filtek Z350 XT), silorane composite (Filtek P90) versus micro-hybrid composite (Filtek Z250 XT). Materials and methods: Ninety primary molars were divided into three equal groups based upon the restorative material tested. Each group was further subdivided into two subgroups of fifteen molars each according to type of procedure performed (class II cavity preparation or pulpotomy). All restored teeth were followed up. The ultra-morphological structure of the restoration-tooth interface was examined by Scanning Electron microscope, and micro-leakage, micro-shear bond strength and compressive strength were measured. Results: Clinical evaluation of the restorative materials revealed a statistically insignificant difference between modified USPHS criteria. Scanning Electron Microscope showed numerous and long infiltrating resin tags for the methacrylate groups (Filtek Z250 and Z350), while fewer and shorter tags for silorane (Filtek P90). Concerning microleakage testing Silorane showed the lowest statistically significant mean microleakage percentage value compared to Z250 and Z350. No statistically significant difference was noted between the three tested materials for microshear bond strength testing. Finally regarding compressive strength testing Filtek Z350 showed the highest mean compressive strength value among the three tested materials. Conclusion: The short term clinical performance of silorane based resin composite Filtek P90 was similar to both methacrylate-based resin composite Filtek Z250 and Filtek Z350. Silorane based composites represent an alternative to conventional methacrylate based composites for direct posterior restorations.