—                             Composite restorations have become a routine procedure for class I and class II lesions. However, polymerization shrinkage and associated stresses remain a genuine problem. The physical mismatch between shrinkage prone restorative material and stiffer tooth structure may result in undesirable clinical situations such as microleakage, marginal staining, gap formation, postoperative sensitivity and enamel microcracks. Several strategies aimed at reducing polymerization shrinkage have been proposed.

—                                            Tetric N-Ceram is a light-curing, radiopaque nano-hybrid composite for restorative treatment. Resin composites based on nano technology have certain advantages such as reduced polymerization shrinkage, increased mechanical properties, better glossy retention and diminished wear.

—                                           SDRâ„¢ Smart Dentin Replacement is a one-component, fluoride-containing, visible light cured, radiopaque flowable resin composite restorative material.It is designed to be used as a base in class I and II restorations. SDRâ„¢ material has handling characteristics typical of a ―flowable composite, but can be placed in 4mm increments with minimal polymerization stress. SDRâ„¢ material has a self-leveling feature that allows intimate adaptation to the prepared cavity walls.   It is designed to be overlayed with a universal/posterior composite.— 

                                   The aim of this clinical study is to determine the clinical performance of the nano hybrid dental composite (Tetric N Ceram) in stress-bearing posterior cavities over a time period of 1 year with the use of SDR smart dentine replacement liner in one group and LC GIC liner in one group.