Influência dos agentes de limpeza cavitária na resistência ao cisalhamento por extrusão de pinos de fibra de vidro cimentados com cimento resinoso autocondicionante

Abstract

The aim of this study was to investigate the influence of root dentine treatment with 2% chlorhexidine and 10% citric acid on bond strength of fiberglass post cemented with self-etching cement. Forty five human single-rooted teeth were selected and sectioned in the cement-enamel junction, standardizing them with 14 mm length. After endodontic treatment the roots were randomly divided in 3 groups (n=15) according to the previous treatment of the root canal: G1, no treatment; G2, application of 2% chlorhexidine (Rioquímica®) for 60s; G3, application of 10% citric acid (Idem per Idem - Farmácia de Manipulação Ltda) for 60s. Subsequently, the self-etching adhesive Single Bond Universal (3M ESPE) was applied in the canals and on the fiberglass post (White Post, FGM) and these ones were cemented with resin cement (RelyX Ultimate - 3M ESPE), and light polymerized for 40s. The roots were sectioned transversely in slides of 2 mm thickness and the push-out test was performed. Data were analyzed by one-way ANOVA and Tukey test (α=0.05) and the types of failures were analyzed under stereomicroscopy (8.0X). The results show that there was no statistically significant difference between the groups, as well as when comparising bond strength in root thirds in each group (p>0.05), however, significant results were found between groups G1 and G2 in the cervical third (p=0.045). Mixed and adhesive failures between cement and dentine were predominant. It can be concluded that the use of 2% chlorhexidine in the root canal can interfere in the fiberglass posts bond strength.