Effect of surface-treatments of fibers-posts on the-bonding to resin-cement

Objective:The aim of this study was to evaluate the influence of surface treatments of fiber glass and carbon fiber posts on the bonding to resin cement. Methods: Forty glass fiber posts (GF) and forty carbon fiber posts (CF) (Reforpost, Angelus) received four surface treatments (n=10): T1- silane; T2- silane and adhesive; T3- 50 µm - aluminum - oxide sandblasting and silane; T4- 50 µm - aluminum - oxide sandblasting, silane and adhesive. Composite resin restorations with 7mm of width, 5mm of length and 1mm of thickness were constructed. The posts were cemented with two indirected composite resin restorations and polymerized bilaterally for forty seconds on each region. The samples were serial cutted with an adhesive area of 1mm2. Then, they were submitted to a test at 0,5 mm/min in a microtensile testing machine (EMIC-DL 2000, São José dos Pinhais, Brazil). After fracture, the specimens were examined under SEM to determine the mode of fracture. Mean microtensile strength values were expressed in Mpa and data were evaluated by factorial analysis (2x4) and Tukey test (p<0.05). Results:There was a significant interaction between the type of post and surface treatment. The results were (Mpa):GFT1: 24.9 ± 5.4a; GFT2: 22.1 ± 5.5a; GFT3: 24.2 ± 4.7a; GFT4: 24.1 ± 3.1a; CFT1: 27.8 ± 7.1a; CFT2: 26.1 ± 11.5ab; CFT3: 24.9 ± 5.38ab; CFT4:18.3 ± 2.1b. Conclusions: It can be concluded that the posts composition doesn't interfere on bond strength to resin cement and the treatment with sole silane application for both posts are sufficient as a surface treatment to adhesive fixation.