Bond Strength to Eroded Enamel and Dentin Using a Universal Adhesive System.

Abstract To evaluate the influence of previous acid etching on the bond strength of a self-etch universal adhesive system on sound and eroded enamel and dentin. Flat enamel and dentin surfaces were obtained from bovine incisors (n = 44) and divided into two groups according to the exposure to erosive conditions: sound (without erosion) and eroded (after erosive challenge with 0.3% citric acid, pH 2.6, 5 min, 4x/day, 5 days). Each group was then divided into two subgroups (n = 11) according to the application or not of 37% phosphoric acid before applying a universal self-etch adhesive. Single Bond universal adhesive (3M ESPE) was applied and composite blocks were built up using Amelogen Plus (Ultradent). Sticks (1 × 1 mm) were obtained and the microtensile bond strength (µTBS) was assessed using a universal testing machine at a speed of 1 mm/min. Data were analyzed with two-way ANOVA and Tukey's tests (p