Microtensile bond strength of dual-cure resin cement to root canal dentin with different curing strategies

The purpose of this study was to measure the bond strength of dual-cure resin cement at different regions of root canal dentin using three kinds of curing method. Thirty-six extracted bovine teeth were used. Each root was sectioned vertically into halves. Their pulpal dentin walls were polished flat and then applied with two dual-cure resin cements (Bistite II, Panavia F), and divided into three curing strategy groups: multi-direction light, one-direction light and no-light. The bonded specimens were sectioned perpendicularly to the long axis of the root into approximately 0.7 mm thick slabs within two-third of the root from the coronal end, and prepared for microtensile bond strength (mu TBS) test. Knoop hardness of the cements was also measured. Within each curing strategy for both dual-cure resin cements, there were no significant differences between the mu TBS values at the coronal third and mid third regions. The effect of curing method on bond strength and KHN was found to be dependent on the material.