Evaluation of Micro-Tensile Bond Strength of A New Resin Composite Restorative Material at Two Different Dentin Depth After Aging (An In-Vitro Study)

Aim: Evaluation of micro-tensile bond strength of new resin composite restorative material to dentin at two different levels of dentin and after aging. Subjects and Methods : Twenty healthy human molar teeth were selected for the study. Flat preparation was done below the DEJ by 0.5mm. (superficial dentin)), and below the DEJ by 1.5 mm. (deep dentin), all teeth restored with (Estelite sigma quick) resin composite. The teeth were divided into four equal groups: group ST1(prepared in superficial dentin level (0.5mm below DEJ) and subjected to cyclic loading fatigue represented 24 hours), group ST2 (prepared in superficial dentin level (0.5mm below DEJ) and subjected to cyclic loading fatigue represented 6 months), group DT1 (prepared in deep dentin level (1.5mm below DEJ) and subjected to cyclic loading fatigue represented 24 hours), and group DT2 (prepared in deep dentin level (1.5mm below DEJ) and subjected to cyclic loading fatigue represented 6 months). Teeth were then sectioned in a mesiodistal and bucco-lingual to obtain beams. Micro-tensile bond strength was measured using universal testing machine. Statistical analysis was performed using Graph pad Instat (Graph pad,Inc); Software for windows. Results: There was a statistically significant difference between the four tested groups, The highest mean value of (MPa) recorded in groups prepared in the superficial dentin level (ST1) group followed by (ST2) group, The data showed there was a statistically significant difference between groups subjected to different cyclic loading time. Conclusion : Estelite sigma quick resin composite has good bond strength especially at superficial dentin depth.