MICROSHEAR BOND STRENGTH OF INDIRECT COMPOSITE RESIN AFTER DIFFERENT SURFACE TREATMENTS (IN-VITRO STUDY)

Abstract

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.