The effect of silane on the bond strengths of fiber posts.

OBJECTIVES: Esthetic posts have been developed to maximize the foundation of esthetic restorations. The purpose of this study was to evaluate the effect of silane on the bond strength of three fiber-reinforced resin posts (fiber posts). METHODS: Fifty-four extracted human maxillary central incisors and canines were endodontically treated. D.T. Light Post (DT, Bisco), FRC Postec (FR, Ivoclar Vivadent), and ParaPost Fiber White (PP, Coltène/Whaledent) were inserted using the resin adhesive system provided by the respective manufacturer. For half of the specimens in each group, the fiber posts were treated with a silane solution (Monobond S, Ivoclar Vivadent). A push-out test was performed on three different sections of each root to measure bond strengths. Data were analyzed with ANOVA and Bonferroni's post hoc test at P<0.05. RESULTS: The use of silane did not result in any statistically significant difference at any level of the root. Silane did not result in any significant different bond strengths (MPa) for each of the posts. When the data were pooled, the use of silane did not result in statistically significant different bond strengths at P>0.403: No silane=12.7+/-8.4; Silane=14.1+/-7.0. The coronal third of the root (17.5+/-6.7) resulted in statistically greater bond strengths than the medium third (12.9+/-6.8) and than the apical third (9.8+/-7.3) at P<0.002 and P<0.0001, respectively. The medium third and the apical third resulted in no statistically significant different bond strengths from each other at P>0.07. The type of post did not result in statistically significant different bond strengths at P>0.417: DT=14.7+/-6.8 MPa; FR=13.3+/-6.6 MPa; PP=12.2+/-6.6 MPa. SIGNIFICANCE: The use of a silane coupling agent did not increase the push-out bond strengths of the three fiber posts used in this study. All posts bonded to root dentin at the same magnitude. Bonding is more predictable at the most coronal level of the root.

Push-out bond strengths of tooth-colored posts bonded with different adhesive systems.

PURPOSE: To evaluate the effect of luting systems and root region on the push-out bond strengths of a glass fiber-reinforced post and a zirconia post. METHODS: Thirty-two extracted human anterior teeth (central incisors and canines) were endodontically treated with lateral condensation of gutta percha and AH26 sealer. Teeth were randomly assigned to eight groups (n = 4 per group). Two post systems from the same manufacturer (Cosmopost, a zirconia post; or FRC Postec, a glass fiber-reinforced post) were placed with a luting system (bonding agent and resin luting agent). C-Post was cemented with One-Step and Post Cement Hi-X was used as the light-polymerized adhesive control. ParaPost Fiber White cemented with ParaPost Adhesive and ParaPost Resin Cement was used as an auto-polymerized adhesive control. The roots were sectioned in equal thirds (apical, middle and cervical). A push-out test was performed in each section to measure regional bond strengths in MPa. Means were analyzed with two-way ANOVA and Duncan's post-hoc test (alpha = 0.05). RESULTS: The fiber posts ranked in the highest statistical subset regardless of the luting system: ParaPost Fiber White (self-cure control), FRC Postec bonded with Excite DSC/Variolink II, FRC Postec bonded with Syntac/Variolink II, FRC Postec bonded with Excite DSC/Experimental Self Cure Cement, and C-Post bonded with One Step/Hi-X. The zirconia post Cosmopost ranked in the lowest subsets regardless of the adhesive system used at P < 0.05. Means for the medium region of the root (5.0 +/- 0.8 MPa) were not statistically different from those obtained either in the cervical or in the apical region. Means for the cervical root region (6.2 +/- 0.9 MPa) were statistically higher than those of the apical region (4.5 +/- 1.1 MPa) at P < 0.001.