Does the surface treatment affect the bond strength of various fibre-post systems to resin-core materials?

The aim of this study was to evaluate the effects of surface treatments on bond strength of resin-core materials to three different types of fibre posts.

Prefabricated glass (FRC Postec, Ivoclar), quartz (DT light, Bisco) and individually formed glass (Everstick, Stick Tech) fibre posts with a coronal diameter of 1.5 mm were randomly divided into three groups according to the surface treatment performed. In Group 1 sandblasting with aluminium oxide particles (Rocatec Pre, 3M Espe) was followed by the application of a silane coupling agent. In Group 2, posts were immersed in 9.6% hydrofluoric acid gel for 60 s and silanized for 60 s. In Group 3, no surface treatment was performed and it served as control. The resin-core material (Biscore, Bisco) or resin composites (Admira, Voco) were applied to the tube in 2-mm thick increments and light-cured for 40 s using a halogen light curing unit. 1 mm thick discs (n=10/per group) were prepared for the micropush-out test. The discs were pushed out in a universal testing machine (Lloyd Instruments). Statistical significance was determined by a multifactorial analysis of variance followed by Tukey's post hoc test or independent t tests.

ANOVA revealed that fibre posts and core materials had a significant effect on micropush-out bond strength values (p<0.001). The surface treatment with hydrofluric acid gel and sandblasting with aluminium oxide particles significantly enhanced bond strength values of fibre posts except Everstick post (p<0.05).

Different surface treatments of fibre posts might affect the bonding capacity of resin-core systems to these posts.