Effects of composite thickness on shear bond strength to dentin
Effects of Composite Thickness on Shear Bond Strength to Dentin Sixty no-carious extracted human molars were used in this study. The enamel on the occlusal surface of the crown of the tooth was removed by a diamond bur then the surfaces of the teeth were ground flat. The teeth were randomly divided into six groups each of ten and then stored in distilled water at 37 degree Celsius. Two types of composite were used in the study, Definite and Tetric. The bonding agents Etch and Prime were prepared and applied according to manufacturer directions and applied to the dentin surface on the first three groups and light cured for 20 seconds. The composite definite was packed into 2, 3 and 4 mm thick using split metal mold in the first, second and third groups respectively and bulk cured from top of the composite for 40 seconds, the same procedure was repeated in the remaining three groups but the composite Tetric was used with its corresponding bonding agent (Excite). The bond strength was measured with Universal Compression Machine. The results showed that there was no significant difference between the two types of composite. The shear bond strength was affected by composite thickness; the 2 mm increment showed higher bond strength than the 3 mm and 4 mm increments in both composites. In conclusion under the condition of this study and for better bond strength of resin composite to dentin it should not be used in an increment more than 2 mm.
|Journal||Mustansiria D J|