Tensile bond strength of dentin adhesives: a comparison of materials and methods

The influence of two different storage conditions on the bond strengths of four dentin adhesives [Gluma, Scotchbond (dual), Scotchbond 2, and Tenure] was studied. 5000 cycles from 7 degrees C to 60 degrees C reduced the bond strength significantly for all materials except Gluma, as compared with that found after 24 h of storage in water at 37 degrees C. The influence of two different tensile test methods and two different locations, i.e., occlusal and buccal, of the dentin substrate on the bond strength of Gluma and Scotchbond 2 was also studied. The type of dentin as well as the choice of tensile test method changed the bond strength values significantly. One method gave as much as 3x higher bond strength values for one material when used on the same type of dentin. Bond strength values obtained on the dentin from the buccal side of the tooth were from 20% to 50% higher than those obtained on occlusally located dentin with the same method.