This study was envisaged to find out a material, which can ideally adhere to tooth surface and eliminate or at least minimize the gap at the tooth-restoration interface, a prime etiological factor of microleakage and resultant secondary dental caries leading to failure of the restorations with three dental restorative materials viz. Glass ionomer cement, silver amalgam and light curable composite resin. This was accomplished by evaluating and comparing microleakage and marginal gap formation in seventy-five human permanent posterior teeth using these three dental restorative materials. The tooth samples were divided into three groups each having twenty-five teeth and restored with one of the three materials. They were thermo-cycled and submerged in methylene blue dye then sectioned to test microleakage and marginal gap formation. The data thus obtained were subjected to statistical analysis. The scores were calculated using ANOVA test and statistical data were compared cross-sectionally. Results showed microleakage at tooth-restoration inter phase with all the materials. They were found in the following decreasing order: group B (SA) > group C (CR) > group A (GIC). Hence, GIC was found best followed by CR and SA
