Push-out bond strength evaluation of a new fibre post system

Objective: Aim of this study was to evaluate the influence of different parameters on push-out bond strength of a new fibre-reinforced composite post (FRCP) system.

Methods: 200 freshly extracted human upper incisors were decapitated, endodontically treated, and received adhesively luted FRCPs (n=10) at 37°C. Selected luting agents for Voco posts were: Futurabond DC+Bifix (FB), Futurabond DC+Rebilda (FR), Voco Self-Adhesive Cement (SC), RelyX Unicem (RU), and Maxcem (MC). For each combination, dual-curing (DC) and chemical curing (CC) alone were evaluated. For the Voco materials, furthermore the influence of silanization, post brand, and post size were investigated. Restored roots were stored in water for X days and cut into slices of XX mm. Push-out bond strengths (PBS) were measured in a Zwick universal testing machine at a crosshead speed of 0.5 mm/min. Results were subdivided into coronal (c) and apical (a) PBS.

Results: PBS in MPa (SD) was as follows: FB-CC-c: 13.9 (3.6) FB-CC-a: 12.5 (4.8) FB-DC-c: 17.2 (3.7) FB-DC-a: 12.5 (3.9) FR-CC-c: 13.0 (4.3) FR-CC-a: 11.2 (3.7) FR-DC-c: 14.1 (4.2) FR-DC-a: 10.9 (3.3) SC-CC-c: 12.0 (4.1) SC-CC-a: 10.2 (3.0) SC-DC-c: 13.0 (3.3) SC-DC-a: 11.4 (3.5) RU-CC-c: 11.3 (3.4) RU-CC-a: 9.4 (4.3) RU-DC-c: 12.4 (3.4) RU-DC-a: 11.1 (3.9) MC-CC-c: 9.1 (3.3) MC-CC-a: 7.5 (2.1) MC-DC-c: 10.0 (3.2) MC-DC-a: 9.8 (3.2). Results of SC were comparable to RU (p>0.05; one-way ANOVA) and superior to MC (p<0.05). Neither brand nor size of posts had any influence on results (p<0.05). Silanization as well exhibited no effect on PBS (p>0.05).

Conclusions: Within the limits of this in vitro study we conclude that both new materials for adhesive post luting exhibited promising results with no influence of silanization, post brand, and post size.

Supported by Voco, Cuxhaven, Germany.