Effects of Luting Cements on Regional Fiber Post Retention

Objectives: To evaluate the regional bond strength of glass fiber posts cemented to root dentin with two different resin cements and adhesive systems, using the push-out test. Material and methods: Fifteen single-rooted bovine teeth with standardized root canal instrumentation were randomly assigned to 3 groups (n=5): G1- etching with 37% phosphoric acid gel (3M/ESPE) + Adper ScotchBond Multi Purpose Plus (3M/ESPE) light cured + #2 glass fiber post (Exacto ¨C Angelus) + conventional resin cement RelyX ARC (3M/ESPE); G2- etching with 37% phosphoric acid gel + Adper ScotchBond Multi Purpose Plus (3M/ESPE) chemically cured + #2 glass fiber post + RelyX ARC (3M/ESPE); G3- #2 glass fiber post + self adhesive resin cement RelyX U100 (3M/ESPE). After 24 hour storage in distilled water at 37°C, specimens were cut into thin slices of 1mm thick and submitted to the push-out test in a universal testing machine (EMIC) at a crosshead speed of 0.5 mm/min. Results: Cementation material had a significant effect on mean push-out strength (p≤0.05). Statistical analysis also showed a significant effect of root region (p≤0.05). Values were higher for the coronal region than for the apical third of the root and the light cured adhesive group showed lower values. Conclusion: The chemically cured use of adhesive system with conventional resin cement provided better retention of the posts, as well as the use of self adhesive resin cement.