Microtensile Bond Strength of Glass Fiber Posts Cemented with Self-adhesive and Self-etching Resin Cements

Purpose: To evaluate the bond strength of glass fiber posts to intraradicular dentin when cemented with self-etching and self-adhesive resin cements. Materials and Methods: Forty-eight single-rooted human teeth were decoronated, endodontically treated, post-space prepared and divided into 8 groups (n = 6). The glass fiber posts used were: Exacto (EA) (Angelus) and everStick (ES) (StichTeck), which were cemented with two self-adhesive resin cements: BisCem (BIS) (Bisco) and Rely-X Unicem (UNI) (3M/ESPE), and two self-etching resin cements: Esthetic Cementing System NAC100 (NAC) (Kuraray) and Panavia-F (PAN) (Kuraray). Specimens were thermocycled between 5°C and 55 °C for 1000 cycles and stored in water at 37°C for 1 month. Four 1-mm-thick (in cross section) rods were obtained from the cervical region of the roots. Specimens were then subjected to microtensile testing in a special machine (BISCO; Schaumburg, IL, USA) or a crosshead speed of 0.5 mm/min. Microtensile bond strength (µTBS) data were analyzed with two-way ANOVA and Tukey's tests. Results: Means (and SD) of µTBS (MPa) were: EA/PAN: 10.3 (4.1), EA/NAC: 14 (5.1) EA/BIS: 16.4 (4.8), EA/UNI: 19.8 (5.1), ES/PAN: 25.9 (6.1), ES/NAC: 29.1 (7), ES/BIS: 28.9 (6), ES/UNI: 30.5 (6.6). ANOVA indicated significant differences among the groups (p 0.001). Mean µTBS values obtained with ES post were significantly higher than those obtained with EA (p 0.001). For EA, Tukey's test indicated that higher µTBS means were obtained with the self-adhesive resin cements (BIS and UNI), which were statistically significantly different (p 0.05) from values obtained with the self-etching resin cements (PAN and NAC). Different cements had no significant effects on the bond strength values of ES post (p > 0.05). µTBS values obtained with ES post were significantly higher than those obtained with EA post irrespective of the resin cement used. Conclusion: everStick posts resulted in the highest mean µTBS values with all cements. Self-adhesive cements performed well in terms of bond strength. Parole chiave: glass-fiber posts, resin cements, microtensile bond strength, root dentin