Enhanced mechanical properties and biosafety evaluation of surface-modified fiberglass-reinforced resin-based composite piles

The purpose of this study is to analyze various surface grafting modifications of fiberglass-reinforced resin based composite piles. In addition, the effects of surface modifications of fiberglass-reinforced resin piles in terms of biosafety and mechanical strength were studied. According to different surface treatment methods, the fiberglass was divided into five groups (A–E): a blank control group, a KH570 processing group, a KH570 processing+Bis-GMA grafting 1 h group, a KH570 processing+Bis-GMA grafting 3 h group and a KH570 processing+Bis-GMA grafting 7 h group. All surface-treated materials were characterized using scanning electron microscope, thermogravimetric analyses and Fourier transform infrared spectrum and mechanical testing using a universal mechanical tester. The biosafety was evaluated by cell viability experiments and repeated oral toxicity tests and Ames tests. The Bis-GMA grafting modification further enhanced the mechanical properties of resin piles. By increasing the grafting time, the grafting effect and mechanical properties were further enhanced. The surfaces grafted for 7 h (Group E) remarkably improved the mechanical properties (flexural strength ~696.24 MPa; flexural load ~185.67N). The graft modifications improved the mechanical properties of fiber pile resin-based materials. The prolonged grafting time further improved the mechanical properties corresponding to enhanced grafting and the formation of a stable interface between fibers and the resin matrix. The surface-modified dental resin-based fiber did not show any signs of toxicity, cytotoxicity or mutagenicity, suggesting the potential biological safety of these materials in the clinical practice.