Adhesion to Bovine Dentin-Surface Characterization

Abstract

X-ray photo-electron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS) were used to characterize the dentin surface, to determine the effects of different pre-conditioning procedures on the elemental composition of the dentin surface, and to investigate the interaction between dentin and a dentin bonding agent (ScotchBond) by studying the changes in the elemental composition of dentin as a result of the interaction. Scanning electron microscopy (SEM) was used to characterize sample surface morphology, which was then correlated with surface elemental composition. The results showed that: (a) the elemental composition of the smear layer was similar to that of the underlying dentin; (b) cleaning with hydrogen-peroxide did not produce any modification in the elemental composition of the dentin surface; and (c) acid-etching led to an almost complete demineralization of the dentin, leaving behind an organic-rich surface. The results suggest that bonding systems that use acid-etching as a pre-conditioning procedure should be based on agents able to interact with the organic components of dentin, since bonding agents that rely on a chelation-to-calcium reaction are unlikely to be successful. The investigation of the interaction between the bonding agent and dentin led to a postulated adhesive-bonding reaction mechanism and suggested a partially cohesive failure in the bonding agent during fracturing of a dentin-bonding-agent-bonded assembly.

Effect of fiber-reinforced composite at the interface on bonding of resin core system to dentin

“…Although bovine and human teeth have different features especially in terms of morphology, several studies have demonstrated similarities between these two types of substrates. In bonding tests, similar results were reported between bovine and human dentin as well as in the number and distribution of dentinal tubules 36,37) . In this study, bovine dentin was chosen as the substrate because of the convenient size of the teeth.…”

Influence of caries infiltrant contamination on shear bond strength of different adhesives to dentin

“…While hydrochloric acid etching is essential for the removal of the surface layer of noncavitated enamel lesions to allow for the penetration of the resin infiltrant into the body of the lesion [15], hydrochloric acid contamination of sound dentin was shown to induce a more severe demineralization even in concentrations below 1% [4] as compared to 37% phosphoric acid. As a consequence of over-etching, the thick layer of demineralised collagen is not capable of being completely impregnated by adhesives containing monomers with relatively high viscosity, such as Bis-GMA [16,17].…”

“…To analyze the potentially adverse effect of the different components of the infiltrant system separately and in combination, the contamination was simulated by applying either hydrochloric acid (15% HCl, Icon Etch), the resin infiltrant (Icon infiltrant) or both. Contamination with hydrochloric acid was restricted to 15 s to avoid severe over-etching of dentin [4].…”

Use of grape seed extract for improving the shear bond strength of total-etching adhesive to bleached enamel

“…Considering a relative error of measurement of 10-20% 14) , exposure of the enamel surface to 35% hydrogen peroxide resulted in little change of oxygen concentration, and application of 15% GSE after bleaching did not elicit an obvious change in oxygen concentration. Simultaneously, the percentage of other elements did not show a change that could have a potent effect on the SBS.…”

“…With the exception of hydrogen, all elements are identifiable during XPS 25) . XPS allows the upper 1 to 10 atomic layers (0.5 to 5 nm, respectively) to be investigated with a detection limit of 0.1-1% and a relative error of 20% 14) . After tooth-bleaching, residual hydrogen peroxide can continue to breakdown into oxygen free radicals which are composed mainly of hydroxyl radicals 26,27) .…”