Bond strength of restorations made using universal adhesive systems in teeth subjected to acid erosion

Abstract

Objectives: To evaluate the strength of different universal adhesive systems in enamel and eroded dentine. Materials and Methods: The experimental units were composed of 30 bovine enamel fragments and 30 bovine dentin fragments randomly divided into three experimental groups of enamel and three groups of dentin. The enamel and dentin samples were submitted to erosive challenge and procedures adhesion with adhesive systems divided into three levels according with universal adhesive systems used (n = 10): Single Bond Universal (3M ESPE), Peak Universal (Ultradent) and Ambar Universal (FGM). Previous the restorations, the enamel and dentin fragments were submitted to erosive challenge in 0.3% citric acid (pH = 2.6) for five minutes, four times per day in five days. A composite resin (Forma, Ultradent) cylinder with 2mm diameter was build-up in each fragment. The shear strength was evaluated in a universal test machine (1mm / min). The obtained values of bond strength (MPa) were analyzed by two-way ANOVA and Bonferroni test (α = 0.05). Results: There was no significant difference between adhesive systems tested on the same substrate. The enamel presented higher values of bond strength than dentin. There was a predominance of cohesive failure in resin in enamel and adhesive failure in dentin. Conclusions: The universal adhesive systems tested showed similar adhesive strength in the same eroded substrate.