Análise da molhabilidade e resistência de união de um sistema adesivo autocondicionante de dois passos em dentina erodida

Abstract

Introduction: A composite resin restoration is indicated in the treatment of dentin erosion lesions and the use of a two-step self etching adhesive system may be ideal to achieve this treatment success. Objective: To evaluate the wettability and bond strength of a two-step self etching adhesive system on eroded dentin. Methodology: Twenty bovine incisors were cleaned and sectioned until root was removed, buccal dentin was exposed, and the palatal pulp chamber was acessed. Half of the samples were exposed to an artificial erosive challenge (n=10) through a protocol of five cycles of alternating shaking in citric acid and distilled water, and the other half, were stored in distilled water for control (n=10). All teeth were subjected to contact angle (º) and wettability measurements using distilled water and Clearfil SE Bond two-step selfetching adhesive (CSEB) primer. Subsequently, they were restored with this same adhesive and with a light-cured resin, and then test sticks were made. The microtensile bond strength test was performed. Results: The mean of contact angles in respect to distilled water was smaller for the sound dentin (42.1º) than for the eroded dentin (58.6º), showing a greater free energy for the first group. The mean of these angles in relation to the adhesive system were similar in healthy dentin (37.4º) and eroded dentin (38.1º), indicating similar wetting. The mean values of bond strength in sound dentin was 14.5 MPa, statistically superior to the mean of 9.6 MPa in eroded dentin. Conclusion: The immediate wettability performance of CSEB was similar on both substrates and the bond strength was better on sound dentin than on artificially eroded dentin.