Cyclic Loading Effect on Bonding of Fiber Posts to Root-Dentin

Objectives: to evaluate the effect of mechanical loading on the microtensile bond strength when luting fiber posts to root canal dentin. Methods: forty maxillary premolars were endodontically treated and the roots were prepared for post cementation using the FRC Postec system. A light-cured composite (Clearfil Photo Core) was used for luting in all groups: Single Bond; Multilink Primer; Clearfil Photo Bond and Clearfil New Bond, followed by a composite core build-up. For each experimental group, half of the specimens were load cycled under 90 N (5000 cycles, 3 cycles/sec). Specimens were cut to obtain beams with the post in the center. Microtensile testing was performed with a universal testing machine at a cross-head speed of 0.5 mm/min. Four representative beams of each group were selected for SEM analysis. Data were analyzed by two way ANOVA and Student Newman Keuls multiple comparisons tests (P<0.05). Results: are listed in the table below.

Means with the same letters are not statistically different at P<0.05. Conclusion: post-and-core restorations bonded with self-cured adhesives systems and light-cured composite are prone to deterioration after cyclic loading. CICYT/FEDER. MAT 2004-06872-C03-02.RED CYTED VIII.J.