Evaluation of shear bond strength (push-out) of glass fiber posts cemented with different resin cements in humid ambient. Pilot study

Objective: The objective of this study was to evaluated the push out shear bond strength of different cements used in the cementation of glass fiber posts in a humid ambient. Methods: For this purpose, 21 human canines had their crowns removed, remaining 15 mm of root length. After the endodontic treatment, the teeth were prepared to receive fiberglass posts. The selected teeth were randomly divided into seven groups: Group I RelyX TM ARC, Group II Enforce, Group III BISCO TM, Group IV DUO-LINK TM, Group V Post Cement, Group VI Variolink II and Group VII RelyX TM U100. Each tooth was sectioned perpendicularly to the long axis of the post with a diamond disc of high speed, obtaining a slice of each depth with a thickness of approximately 1 mm, obtained from 1 mm, 5 mm and 9 mm from the cervical limit of each root, resulting in 63 specimens. Microscopic analysis was performed on three levels: superficial, medium and apical. After the microscopic analysis, the specimens were evaluated using the pushout test. Results: Two way Anova showed statistically significant differences among the teeth thirds, cements and their interaction (p < 0.05). The Tukey test showed that the self-adhesive resin cement (Bisco and U100) and the cervical radicular third showed significantly higher results in the push-out test (p < 0.05). Photomicrographs showed that there were greater cracks in the apical and middle region, than in the cervical regions. Conclusion: The results of this study showed that the self-adhesive cements showed superior results when compared to adhesives cements. The cervical root area showed the best results in the push out test. Key-words: Resin cements. Post and core technique. Dental prosthesis.