Influence of different final irrigation protocols for removal of photosensitizer activaded by ultrasonic device on the bond strength of gutta-percha/bioceramic sealer and fiberglass posts/self-adhesive cement

Introduction the role of endodontic treatment is to eliminate microorganisms without compromising adjacent tissues and adhesion. The aim of present study was to evaluate the influence of final irrigation protocols for removal of photosensitizer activaded by ultrasonic device(US) on the bond strength(BS) of gutta-percha/bioceramic sealer and fiberglass posts/self-adhesive cement to root dentin. Methods one hundred single-rooted teeth were used. After coronal sectioning, 50 roots were used to assess the bond strength of filling material and 50 to assess the bond strength of restorative material. After sample preparation and photodynamic therapy protocol with US, the roots were randomly divided into five groups (n = 10), according to irrigation protocol for photosensitizer removal: G1(negative control)–distilled water + US;G2–17% EDTA;G3–17% GA;G4 − 17% EDTA + US;G5–17% GA + US. Then, the roots were filled with gutta-percha/Bio-C bioceramic sealer in the first evaluation, and fiber glass posts/Rely-X U200 self-adhesive cement in the second evaluation. In both, the roots were sectioned to obtain 1 mm thick dentin discs containing the filling/restorative material, and the push-out test was performed. Failure patterns were observed under optical microscope. Specific statistical analysis was performed in both evaluations(α 5%). Results in both evaluations, BS was significantly higher in groups 4(17% EDTA + US) and 5(17% GA + US) when compared to all other groups(p < 0.05). Regarding the failure patterns, no statistically significant difference was found between groups (p > 0.05), with a predominance of cohesive failure in all groups. Conclusion the association of US with EDTA and GA for photosensitizer removal improved the BS of filling/restorative material to root dentin.