Aging affects the adhesive interface of posts luted with self-adhesive cements: a 1-year study.

Purpose: To examine the bond strength and interfacial nanoleakage expression of fiber posts luted to intraradicular dentin with self-adhesive cements. Six-month and 1-year aging effects were examined.

Materials And Methods: Post space was created in endodontically treated human incisors. Each tooth was assigned to a self-adhesive cement/post combination: (1) Bifix SE Cement (Voco) with proprietary posts (Rebilda Post, Voco), (2) RelyX Unicem (3M ESPE) with proprietary posts (Rely X Fiber Post, 3M ESPE), (3) MaxCem (Kerr) with Rebilda Posts. Each specimen was cut into 1-mm-thick sections and either immediately stressed to failure with the push-out bond strength test or aged in artificial saliva for 6 months or 1 year before testing. Additional specimens were processed for quantitative interfacial nanoleakage analysis using ammoniacal silver nitrate.

Results: Immediate bond strength ranked in the following order: Bifix SE (7.8 ± 2.9 MPa) = RelyX Unicem (8.4 ± 2.7 MPa) > MaxCem (4.6 ± 2.4 MPa) (p < 0.05). Aging significantly reduced the bond strength of all cements after 1 year: Bifix SE (3.8 ± 1.4 MPa) = RelyX Unicem (5.8 ± 1.7 MPa) > MaxCem (1.3 ± 0.9 MPa; p<0.05). No immediate difference in interfacial nanoleakage expression was found. Nanoleakage increased after aging, and MaxCem showed the highest values.

Conclusion: The push-out strength and interfacial nanoleakage expression of fiber posts luted with self-adhesive cements were dependent on luting material and type of post, and were significantly affected by storage time.