Influência de métodos de limpeza do canal radicular na resistência de união de pinos de fibra de vidro após obturação e fixação empregando diferentes materiais

Abstract

For the restorative treatment of endodontically treated teeth, it is often necessary to use intraradicular retainers, such as those reinforced by fiberglass. Different materials have been recommended for these situations, such as bioceramic endodontic cement for filling root canals, considered an ideal cement, and universal resin cement for fixing retainers, which promises better adhesion. Thus, the objective of this study was to compare the bond strength of fiberglass posts to the dentin of canals filled with different endodontic cements, with the retainers being fixed with different resin cements, after a conventional or additional post-relief cleaning process. For this, 80 bovine incisors were instrumented with manual files and divided according to: type of endodontic cement, based on calcium hydroxide (HC) or bioceramic (BC); cleaning method, conventional (CN) or with Easy Clean system (EC); and type of fixation material, self-adhesive resin cement RelyX U200 (R2) or universal resin cement RelyX Universal (RU). The specimens were sectioned, resulting in two slices (1.0 mm) for each root third, and the values of bond strength were verified by micro-push out test and failure modes analyzed. Data were verified using three-way analysis of variance in repeated measures followed by Tukey HSD test (p<0.05). The cleaning method factor affected the bond strength values (p=0.007), with better results for the groups subjected to additional cleaning (EC). Regarding the endodontic cement variable, the groups filled with bioceramic cement (BC) presented the highest bond strength values (p<0.001). There was no significant interaction between resin cements (p=0.359) and no significant differences in bond strength for the different root thirds (p>0.005), regardless of the endodontic cement. The bioceramic cement achieved superior bond strength values, the cleaning protocols by agitating the solutions with easy clean files positively influenced the adhesion of the fiberglass posts, the new RelyX Universal resin cement was able to obtain results of bond strengths similar to the gold standard RelyX U200.