An investigation on the shear bond strength of three dentine adhesives.

The aim of this investigation was to compare the shear bond strengths of three dentine adhesives tested using an Instron Universal Testing machine at a crosshead speed of 0.5 mm/min. Sixty human molar teeth were used and divided into 3 equal groups where the occlusal surfaces were ground and adhesives were applied overlaid by composite material. Samples were fixed to the Universal Testing machine. Results were recorded in kg/cm2 and converted into MPa units then tabulated and statistically analyzed. Duncan's multiple range statistic test at p < 0.05 showed no statistically significant difference between the shear bond strength values of Scotchbond 2 and Amalgambond; whereas the shear bond strength values of Scotchbond 2 and Amalgambond were significantly higher than those of Gluma. Scanning electron microscopic examinations at X10 and X2500 magnifications showed a dominant adhesive pattern of failure in the samples treated with Gluma, and a mixture of cohesive and adhesive-cohesive patterns of failures in the samples treated with Scotchbond 2 and cohesive patterns of failures in the samples treated with Scotchbond 2 and Amalgambond.