Abstract
The purpose of this study was to investigate the effect of Ca (OH) 2, paste on bond strength of a self-etching priming adhesive system (Mega Bond) to root canal dentin. Calcium hydroxide paste was medicated into root canals of human extracted incisors and the teeth were stored in water at 37°C for 1, 7 and 30 days after sealing of orifices. After storage, root canals were rinsed by saline. The medicated teeth and control teeth, which have no medication and storage, were treated with Mega Bond and filled with resin composite according to manufactures' instructions. After immersion in water at 37°C for 24h, the teeth were serially sectioned into multiple slices and the micro-tensile bond strengths were measured. Surfaces of root canal dentin and resin-dentin interfaces in each group were also observed in SEM. The bond strengths to root canal dentin for 7 and 30 days group were significantly lower than those of control group (p<0.05, one-way ANOVA and Dunnett test). No morphological changes at resin-dentin interface were observed among all groups. Remnants of Ca (OH) 2 paste on the surface of root canal dentin were observed for 7 and 30-day groups. In conclusion, it is necessary for good adhesion to root canal dentin to completely remove Ca (OH) 2 paste.
