Hydrolytic Stability of Self-etch Adhesives Bonded to Dentin

Abstract

Functional monomers chemically interact with hydroxyapatite that remains within submicron hybrid layers produced by mild self-etch adhesives. The functional monomer 10-MDP interacts most intensively with hydroxyapatite, and its calcium salt appeared most hydrolytically stable, as compared with 4-MET and phenyl-P. We investigated the hypothesis that additional chemical interaction of self-etch adhesives improves bond stability. The micro-tensile bond strength (muTBS) of the 10-MDP-based adhesive did not decrease significantly after 100,000 cycles, but did after 50,000 and 30,000 cycles, respectively, for the 4-MET-based and the phenyl-P-based adhesives. Likewise, the interfacial ultrastructure was unchanged after 100,000 thermocycles for the 10-MDP-based adhesive, while that of both the 4-MET- and phenyl-P-based adhesives contained voids and less-defined collagen. The findings of this study support the concept that long-term durability of adhesive-dentin bonds depends on the chemical bonding potential of the functional monomer.

Bonding efficiency and durability: current possibilities

“…5,59 Such chemical bond is mostly observed in mild and ultra-mild SE adhesives (pH < 2) that partially demineralizes dentin producing sub-micrometer hybrid layers 14 in which substantial HAp-crystals remain around partially exposed collagen fibers. 3,18,60,61 Besides protecting collagen fibers against degradation, such remaining mineral content also serves as receptor for additional chemical bonding with the respective functional monomer, 14,18 by which their two-fold bonding mechanism (i.e. micro-mechanical and chemical adhesion) closely resembles that of glass-ionomers.…”

Resin–Dentin Bonding Interface After Photochemical Surface Treatment

“…Additionally, the organic debris might also be a reason for nanoleakage in the same manner that resin-impregnated smear layer formed in conventional self-etching procedure would cause nanoleakage. [26][27][28][29][30][31] Because it is known that such debris can be controlled by modifying atmospheric conditions at the irradiation field, 23 the quality of bonding strength following ArF excimer laser treatment might be further improved under decompression.…”

Effects of One-year Storage in Water on Bond Strength of Self-etching Adhesives to Enamel and Dentin

“…This was a rather unusual result for a bonding system which already exhibited good initial bond strength. In previous studies, at best only a slight increase in bond strength was reported after long-term storage [19][20][21][22] . It has been suggested that loss of minerals from enamel and dentin during in vitro water storage would lead to deterioration of mechanical properties of teeth 31) .…”

“…Susceptibility of resin components to hydrolysis has been identified as a cause for decrease of bond strength. It has been suggested that the outstanding hydrolytic stability of MDP and its additional chemical interaction with enamel and dentin contributed to the long-term durability of dentin and enamel bonding with SE 17,21) and TS 18,22) . MDP has a special molecular structure that enables chemical interaction with residual hydroxyapatite after etching, and the calcium salts formed thereby also exhibit hydrolytic stabiltiy 21) .…”

“…It has been suggested that the outstanding hydrolytic stability of MDP and its additional chemical interaction with enamel and dentin contributed to the long-term durability of dentin and enamel bonding with SE 17,21) and TS 18,22) . MDP has a special molecular structure that enables chemical interaction with residual hydroxyapatite after etching, and the calcium salts formed thereby also exhibit hydrolytic stabiltiy 21) . The materials used in this study were classified as mild self-etching systems with pH values circa 2.0 and higher: 2.0, 2.0, and 2.7 for SE 6) , PB 23) , and TS 6) respectively.…”