Effect of surface treatment on roughness and bond strength of CAD‐CAM multidirectional glass fiber‐reinforced composite resin used for implant‐supported prostheses

The study evaluated the effect of different surface treatments on the surface roughness of a new‐generation fiber‐reinforced CAD‐CAM composite resin (FRC) and its bond strength to veneered composite resin. Fifty specimens (10 mm × 10 mm × 1 mm) were prepared from FRC blocks (Trinia; Shofu) and embedded in acrylic resin. The specimens were divided into five groups ( n  = 10) for different surface treatments: nontreated (control), Al 2 O 3 airborne particle abrasion, silica coating (Cojet), acid etching (H 2 SO 4 ) and hydrogen peroxide (H 2 O 2 ) application. Surface roughness ( R a ) of the specimens was measured using a profilometer. A veneering composite resin (3 mm in diameter by 4 mm in length) was applied on the specimens. The shear bond strength between the FRC and the veneering resin was measured. A one‐way analysis of variance was used to analyze the data. The differences among the groups were analyzed with Dunn post hoc tests ( α  = 0.05). Surface treatments increased the surface roughness, and Al 2 O 3 airborne particle abrasion resulted in the highest R a value followed by H 2 SO 4 , Cojet, H 2 O 2 and control group ( P  < 0.05). The highest shear bond strength was achieved with Al 2 O 3 application ( P  < 0.05). Cojet and H 2 O 2 applications resulted in higher shear bond strength than the control ( P  < 0.05). H 2 SO 4 application resulted in lower bond strength than the control ( P  < 0.05). Surface treatments increased the surface roughness of FRC. Al 2 O 3 and silica coating increased the surface roughness more than the chemical applications. The tested surface treatments can be used to increase the bond strength except for the H 2 SO 4 application. © 2021 Society of Chemical Industry