Effects Of Dentin Deproteinization On Resin-dentin Bond Properties

It has been well recognized that proper modification of the bonding surface of dental hard tissue is critical to achieve good bond between resin and tooth structure. Since the introduction of acid-etching technique by Buonocore in 1955, adhesive dentistry has made great advances. By acid etching, the enamel was changed into a highly mineralized alveolar coarse surface, which was the key factor for achieve stable and reliable adhesion to resin. Meanwhile, phosphoric acid or organic acid was required when current dentin adhesive systems were used, to deminralize dentin surface, exposing collagen fibrils network. The infiltration of resin monomer into the demineralized collagen network resulted in the formation of the hybrid layer, which was believed to be one of the most effective mechanisms in dentin bonding. However, the collagen fibril network of deminralized dentin represents a soft delicate bonding substrate that may contribute to the technique sensitivity of bonding procedure; and the incomplete penetration of the resin monomer would result in nanoleakage, which could act as pathway for water and enzymes to enter into the bonding interface; the uncapsulated collagen fibrils in the demineralized dentin is susceptible to hydrolysis and enzymatic degradation. Giving the fact that resin bonding to enamel is superior to dentin, therefore it is of great interest to change dentin into an enamel-like bonding substrate.Dentin deproteinization is a new bonding technique to improve the bonding properties of dentin with the use of hypochlorite (NaOCl) to dissolve the exposed collagen fibrils of deminralized dentin. Previous studies have shown bonding to deproteinized dentin resulted in increased bond strength. Further study showed that the higher the concentration of NaOCl, the greater the dentin bond...