Resin-Bond to Root Dentin: Accessory Posts And Dentin Hybridization Effect

Objective: To evaluate the influence of accessory fiber posts (AFP) and intraradicular dentin hybridization (IDH) on the push-out bond strength of fiber post luted with resin cement to bovine root dentin. The null hypotheses were that the AFP using and IDH do not affect the push-out bond strength. Methods: The canals of forty single-root bovine roots (16mm in length) were prepared at 12mm using the preparation drill (N0 3, RTD, France). With an assistance of a modifier parallelometer, each root had your apical region (4 mm length) embedded in acrylic resin and the roots were randomically divided into four groups, according the luting procedures (N=10): Gr1- IDH + fiber post n0 3; Gr2- IDH + fiber post n0 1; Gr3- IDH + fiber post n0 1 + AFP; Gr4- Fiber post n0 3 without IDH. Except for the group Gr4, the specimens (sps) were treated with the adhesive system (All Bond 2) and the fiber posts (Macro- Lock Illusion) were luted (Duolink) and after stored in distilled water prior the mechanical test (24 h, 37°C). Each specimen was cut in 4 disc samples (1.8 mm in thickness), which were submitted to the push-out test on a universal test machine (EMIC, model DL-1000) at a speed of 1mm/min. The data (MPa) were analyzed statistically by one-way analysis of variance (ANOVA). Results: The means (± standard deviation) values obtained after push out test were: Gr1- 5.4±1.3 MPa; Gr2- 4.2±2.4 MPa; Gr3- 4.6±1.5 MPa; Gr4- 3.3±1.7 MPa. The statistical analysis didn't observe influence among the groups (p=0.0966> 0.05). The null hypotheses were accepted. Conclusion: The AFP and the IDH do not improve the bond strength of fiber post luted to bovine root dentin.