Introduction: An essential part in the clinical success of any indirect restoration is bond strength. Several surface treatments might be used to enhance bond strength between indirect composite restorations and resin cement.
Objectives: This study aims to calculate microshear bond strength of two different types of indirect composite resin after different surface treatment protocols before cementation.
Material and Methods: Sixty cylindrical specimens were prepared from two types of indirect composite and divided into 2 groups (n=30). Group A: SR NEXCO and Group B: Gradia Plus Indirect composite. Each group was subdivided into three subgroups according to their surface treatment: subgroup 1A (sandblasting by aluminum oxide particles followed by sailne), subgroup 2A (sandblasting by aluminum oxide particles + Hydrofluric acid etching+sailne) and subgroup 3A (sandblasting by aluminum oxide particles + MONOBOND Etch and prime) same surface treatments were used at subgroups 1B, 2B&3B respectively. The treated composite specimens were cemented to a flat dentin surface of 10 molar teeth using G-CEM LINKACETM. All the samples were thermocycled for 500 cycles from 5 to 55C, and then microshear bond strength test was done in a Universal Testing Machine 0.5 mm/min.
RESULTS: Statistical significant difference was found between subgroups 1A and 2A (p=0.043) and between subgroups 1A and 3A (p=0.013) .Moreover, there was a significant difference between subgroups 1B and 2B (p1=0.002) and between subgroups 1B and 3B (p2=0.044).
Conclusion: Sandblasted subgroups with aluminum oxide particles followed by silane recorded the highest microshear bond strength values regardless of the type of composite.