Aims & Objectives: To compare the effect of acid etching on the tensile bond strength of composite resin to various glass ionomer cements. Materials and Methods: Sixty extracted molars (maxillary and mandibular) were prepared for this study by flattening all the cusps to give the shape of the crown as a block. These sixty samples were divided in six groups having ten samples in each group. They were as follows: Group 1- Conventional GIC with acid etching, Group 2- Conventional GIC without acid etching, Group 3- Light cured RMGIC with acid etching, Group 4- Light cured RMGIC without acid etching, Group 5- Self cured RMGIC with acid etching, Group 6- Self cured RMGIC without acid etching. Results: The results showed no significant differences between any of the six groups, showing that application of 37% phosphoric acid did not result in significant bond strength between Glass Ionomer cement and composite resin. Conclusion: Acid etching by 37% phosphoric acid on glass ionomer cement surface did not improve the tensile bond strength of conventional, light cured resin modified and self cured resin modified glass ionomer cement to composite resin
