Effect of different surface treatments of luted fiber posts on push out bond strength to root dentin

Purpose: The purpose of this in vitro study was to evaluate the influence of different post surface treatments on the micro push out bond strength of a luting agent to a fiber post. Materials and methods: Sixty freshly extracted single rooted upper central incisor teeth were selected, cut perpendicular to the long axis at the labial cemento-enamel junction. All root canals were instrumented, obturated, the post spaces were prepared to a depth of 11 mm. The specimens were classified into five groups according to the surface treatment performed to the post. Group 1:- no surface treatments (control group), Group 2:-surface treatment with chloroform, Group 3:-surface treatment as in group 2 in addition to the application of silane coupling agent (Calibra), Group 4:-surface treatment by sandblasting using 50 µm alumina particles, Group 5:-surface treatment as in group 4 in addition to the application of silane coupling agent (Calibra), A dualpolymerizing resin luting agent (Calibra) was used for cementation of posts. Three segments (1 mm each) from the cervical 1/3 of each root were obtained. Micro push out test was performed on a universal testing machine at a cross-head speed of 1.0 mm/min until bond failure occurred. Data were analyzed with 1-way ANOVA. Results: Micro push out bond strength of the luting agent to the post was significantly affected by surface treatment (P 0.05). Treating the surface of the post with airborne-particle abrasion followed by silanization resulted in the highest bond strength compared with other treatments. There was no significant difference in bond strength between the chloroform group before and after silanization. Conclusions: Airborne-particle abrasion in addition to silanization provided the highest increase in bond strength between the fiber post and the resin luting agent evaluated.