Effect of Aging on Mineral Content of Resin-Dentin Interface Treated with Total Etch Adhesives

Abstract

Background/Aim: Slow release of fluoride from adhesives might increase the concentration of fluorapatite in the hybrid layer and the underlying dentin and subsequently could stabilize the adhesive interface. The present study aimed to evaluate the effect of aging on the mineral content of the bonded resin/dentin interface and to compare between two similar commercial adhesive systems. Materials and Methods: This in vitro study was carried out on 20 caries-free upper and lower human molar teeth. All the procedures of acid etching, application of adhesives and resin composite buildup were only restricted to dentin. Each tooth was prepared to receive Adper Single Bond 2 on one half (Group I) and Prime & Bond NT on the other half (Group II). Sticks from the same tooth half were randomly divided into 3 subgroups according to storage time regimen: immediate, 3 months and 9 months in deionized water. The mineral content at resin-dentin interfaces were analyzed using an environmental scanning electron microscope and expressed as a atom percentage of the total area evaluated. One-way ANOVA test was used to determine the significant effect of aging on the mineral content of resin-dentin interface. Comparison between the two adhesives at different time intervals was done using independent student t test. Results: There was significant difference among different follow up intervals regarding the mineral content of Group I (p=0.040), while Group II showed non-significant difference (p=0.093). There was non-significant difference between the two adhesives in all storage periods, except at 9 months (p=0.050).