Comparison of Bio-degradation for Ridge Preservation Using Silk Fibroin-based Grafts and a Collagen Plug.

A material for ridge preservation should have dimensional stability to resist bio-degradation. This study was designed to compare bio-degradation of ridge preservation materials. Collagen plug was used as a positive control. Untreated, ethanol-treated, and 4-hexylresorcinol (4HR)-treated silk plugs were used for the experimental group. Each material underwent a scanning electron microscopic exam and a Fourier transform infrared (FT-IR) spectroscopic exam. Bio-degradation was evaluated by analyzing cylindrical bony defects in rabbit tibias. There were no prominent differences in microstructure among the silk plug groups. FT-IR exam demonstrated that the ethanol- and 4HR-treated silk plug groups had enhanced β-sheet structure. All silk plug groups exhibited significantly higher residual graft than the collagen plug group 4 weeks postoperative (p < 0.05). In conclusion, silk fibroin-based ridge preservation material was less bio-degradable than a collagen plug until at least 4 weeks after grafting.