BACKGROUND The aim of this study is to evaluate the effect of different combinations of various surface treatments on the shear bond strength (SBS) of repaired composite resin. METHODS A total of 122 composite samples were prepared from Filtek Z350 XT. Samples were light cured and stored for 6 weeks. Surface treatment of old composite was done in five groups: Group I: bur roughening + phosphoric acid etching, group II: bur roughening + hydrofluoric acid etching + silane coupling agent, group II: air abrasion + phosphoric acid etching, group IV: air abrasion + phosphoric acid etching + silane coupling agent, group V: air abrasion + hydrofluoric acid etching + silane coupling agent. Bonding agent was applied to all surface-treated old composites and light cured. The fresh composite resin was bonded to treated surfaces and cured and stored in water at 37°C for 6 weeks. Shear bond strength was measured by a universal testing machine. RESULTS Shear bond strength values of all groups were not statistically significant except for group V, which showed statistically significant higher SBS than group III. CONCLUSIONS Techniques with readily available materials at the clinic can attain similar SBS to more elaborate technique involving potentially hazardous materials.