Evaluation of Micro-Tensile Bond Strength of New Composite Resins With Dentin. An In Vitro Study

Aim: to evaluate micro tensile bond strength of new generation composite resins with dentin. Methods: Extracted human premolars teeth (n=48)were used to preper one hundred and sixty eight sticks .Specimens divided into two equal main groups according to types of composite used (A1; Xtra fil bulk-fill and A2; Tetric-N- Ceram bulk-fill). Then each main group were subdivided according the adhesive approach used into two equal subgroups (B1; total each and B2; self-etch). According to dentin depths each subgroup were further categorized into two equal categories according to dentin depths (C1; superficial and C2; deep). The μ-tensile bond strength was evaluated using universal testing machine at a crosshead speed of 0.5 mm/min. until failure occurred. Data were recorded, tabulated and statistically analysed.. Results: showed significant (p<0.05) effect of composite and dentin level on μ-tensile bond strength, while the effect of adhesive showed non-significant (p>0.05) dentin.Conclusion: Xtra-Fill bulk-fill has higher bond strength than Tetric Bulk- fill. Additionally, Total- etch adhesive system has higher bond strength than self-etch with the superficial dentin while self-etch adhesive system has higher bond strength with the deep dentin