Abstract
The effect of surface pretreatment with H3PO4 and NaOCl on dentin and the adhesive mechanism were investigated. Although shear bond strength decreased after application of thermal stress in both cases of ground dentin and dentin pretreated with H3PO4 alone, there was no decrease in shear bond strength when dentin was pretreated with H3PO4 and NaOCl even after thermal stress was applied 50, 000 times. According to ESCA analysis, and SEM and' TEM observations, dentin pretreated with H3PO4 and NaOCl appeared to remain intact. The surface was also free of collagen denatured by H3PO4 treatment and appeared smoother with opened tubules and a rough construction. A hybrid layer which is contained resin-encapsulated hydroxylapatite was created in relatively intact dentin.
