Influence of chemical surface treatments on adhesion of fiber posts to composite resin core materials

Objective. This study evaluated the effect of different chemical surface treatments on the adhesion of resin-core materials to methacrylate resin-based glass fiber posts. Methods. Two types of glass fiber posts (Reblida post; VOCO and RelyX post; 3M ESPE) were divided into eight groups according to the surface treatment used; Gr 1 (control; no surface treatment), Gr 2 (silanization for 60 s), Gr 3 (10% H2O2 for 5 min), Gr 4 (10% H2O2 for 10 min), Gr 5 (30% H2O2 for 5 min), Gr 6 (30% H2O2 for 10 min), Gr 7 (CH2Cl2 for 5 min) and Gr 8 (CH2Cl2 for 10 min). Two resin core materials (Grandio DC; VOCO and Filtek P60; 3M ESPE) were applied to each group for testing the adhesion using micropush-out test. Failure types were examined with stereomicroscope and surface morphology of the posts was characterized after treatment using a scanning electron microscope (SEM). Data were analyzed using ANOVA and Tukey's test. Results. The type of post, surface treatment, and core material showed a significant effect on the micropush-out bond strength (P < 0.001). Groups treated with CH2Cl2 or 30% H2O2 solutions for 5 or 10 min showed the highest adhesion values for both types of posts with the core materials tested. Stereomicroscope showed that most failure modes were adhesive type of failures between post and core material. SEM analysis revealed that the fiber post surfaces were modified after chemical surface treatments. Significance. Application of CH2Cl2 or 30% H2O2 to the fiber post surfaces enhanced the adhesion to resin cores. (C) 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.