Push-out Bond Strength Evaluation of Glass Fiber Posts Cementation With Different Resin Cements and Application Techniques

Objectives: The purpose of this study was to evaluate the push-out strength of two different adhesive cements (total-etch and self-adhesive), for glass fiber post (GFP) cementation, using two different techniques (microbrush and elongation tip) of cement application. In addition, this study evaluated the effect of total-etch conditioning before the use of a self-adhesive cement.
Methods: Sixty premolars specimens with a single root canal were selected, endodontically treated and shaped for GFP cementation. The specimens were randomly placed into one of six groups according cement and technique used: RelyX ARC (ARC): ARC + microbrush; ARC + elongation tip; RelyX Unicem (RU): RU + microbrush, RU + elongation tip; RelyX Unicem + 37% phosphoric acid (RUE): RUE + microbrush; RUE + elongation tip. Each specimen root was cut perpendicular to the vertical axis yielding six 1.0 mm thick sections. Push-out strength test was performed, followed by statistical analysis using three-way ANOVA and the Games-Howell test (p<.05).
Results: Statistically significant differences between the groups were found (P< 0.05). The cervical third of the roots had the highest mean push-out strength values, while the apical third had the lowest mean values, regardless of the technique used. The elongation technique produced higher mean push-out strength values compared to the microbrush technique. The self-etch adhesive cement had the highest mean push-out strength value in all thirds. The addition of conditioning step before the self-etch adhesive cementation appears to be effective in enhancing push-out strength with glass fiber posts.
Conclusions: The elongation technique produced higher mean push-out strength values compared to the microbrush technique. The self-etch adhesive cement had the highest mean push-out strength value in all thirds. The addition of conditioning step before the self-etch adhesive cementation appears to be effective in enhancing push-out strength with glass fiber posts.