Bond Strength of Adhesive Luting Agents to Caries-affected Dentin

Abstract

Caries-affected dentin could remain during conservative preparation for indirect restorations. However, the reduced bond strength of adhesive luting agents to this altered substrate might affect the longevity of restorations. SUMMARYIntroduction: The aim of this study was to evaluate the bond strength of adhesive luting agents to caries-affected dentin (CAD). Methods: Forty human molars were sectioned to create dental slices presenting exposed occlusal dentin. Half of the samples were submitted to eight caries-induction demineralizing/mineralizing cycles. The pH-cycling model consisted of three hours in a demineralizing solution followed by 45 hours of immersion in a mineralizing solution. Dentin hardness was measured before and after the pH cycling. Resin cement cylinders were built up over the dentin surface using RelyX Unicem or RelyX ARC/ Scotchbond Multipurpose Plus. The cement cylinders were submitted to shear load, and the data were analyzed using two-way analysis of variance (ANOVA) and Tukey test (p,0.05).

Bonding of Adhesive Luting Agents to Caries-affected Dentin Induced by a Microcosm Biofilm Model

“…Other studies evaluating these two SARCs applied to sound dentin have had similar findings. 19,35,36 Differences in the composition of these two materials may explain these results. BisCem contains the highly hydrophilic monomer HEMA.…”

“…[14][15][16][17][18] By contrast, few studies have evaluated the bond strength of SARCs applied to CAD, and their results have been conflicting. 19,20 A recent study found no difference in SARC bond strength between natural CAD and sound dentin, 20 whereas another study using a pHcycling model to produce CAD found reduced bond strength to this substrate. 19 A difficulty of evaluating the bond strength of adhesive materials applied to CAD is standardizing the dentin substrate.…”

“…19,20 A recent study found no difference in SARC bond strength between natural CAD and sound dentin, 20 whereas another study using a pHcycling model to produce CAD found reduced bond strength to this substrate. 19 A difficulty of evaluating the bond strength of adhesive materials applied to CAD is standardizing the dentin substrate. Use of natural CAD is difficult because different areas of the substrate can exhibit significant differences in mineral content.…”

“…14,21 Several studies have used the pH-cycling method to artificially induce CAD formation. 19,22,23 The use of a microcosm biofilm model is another approach for in vitro formation of CAD. 24 Thus, the aim of this study was to evaluate the bond strength of adhesive luting agents applied to CAD induced by a microcosm biofilm model.…”

Impairment of resin cement application on the bond strength of indirect composite restorations

“…12,13 The group, where restorations were cemented with regular cement, demonstrated better results when compared to self-adhesive resin cement groups, especially when the three-step etch-and-rinse adhesive system was applied, as previously shown. 14,15,16 Despite the low initial pH of the self-adhesive resin cement used, it presents low demineralization effect, and consequently, inadequate formation of the hybrid layer, 17,18 thus explaining the low bond strength values. On the basis of these results, the second hypothesis investigated, according to which the cementation strategy (type of resin cement) directly influences the bond strength of cemented composite resin restorations, can be accepted.…”