Effect of different surface treatments on the bond strength of fiber posts to various core materials

The present study evaluated the effect of different surface treatments of fiber posts on the micro-push-out force between posts and various composite core materials. A total of 80 fiber posts were divided into 16 groups according to the surface treatment and core material. Four different surface treatments were applied on fiber posts including Al2O3 sandblasting, CoJet sandblasting, ytterbium-doped fiber (YbPL) laser roughening, and control (no surface treatment). The core materials were Bis Core, Core Flo, Clearfil DC Core, and Clearfil Photo Core, which were applied in a transparent mold on the surface-treated posts. The light was applied for a total period of 120 seconds. Four 1-mm sections were obtained from each post-core structure. The micro-push-out test was then performed and the results were recorded in Newtons and converted to megapascals (MPa). The type of surface treatment (P<0.001) and core material (P<0.001) significantly affected the bond strength. The highest bond strength was found in the combined application of Al2O3 sandblasting and Core Flo material (132.84 MPa) and the lowest was observed in YbPL laser-treated posts combined with Bis Core material (59.46 MPa). Among the core materials, Clearfil Photo Core showed the highest bond strength with no significant difference from the Core Flo material. Clearfil Photo Core or Core Flo may be preferred for clinical use. Among the surface treatments, sandblasting with Al2O3 showed the highest bond strength.  (J Dent Mater Tech 2023;12(2): 61-67)