Bone-bonding ability of P2O5-Free CaO · SiO2glasses

✍ Scribed by Ohura, Kouichiro ;Nakamura, Takashi ;Yamamuro, Takao ;Kokubo, Tadashi ;Ebisawa, Yukihiro ;Kotoura, Yoshihiko ;Oka, Masanori

• Publisher: John Wiley and Sons
• Year: 1991
• Tongue: English
• Weight: 509 KB
• Volume: 25
• Category: Article
• ISSN: 0021-9304
• DOI: 10.1002/jbm.820250307

✦ Synopsis

Abstract

An apatite‐ and wollastonite‐containing glass‐ceramic (A · W‐GC) has been reported to form a tight bond with living bone through an apatite layer formed on its surface. This layer is considered to be formed by dissolution of Ca^2+^ and HSiO~3~^−^ ions from the glass‐ceramic into the surrounding body fluids. In order to confirm this proposed mechanism for the surface reaction of A · W‐GC, three kinds of glass in the systems CaOSiO~2~, CaOSiO~2~CaF~2~, and CaOSiO~2~P~2~O~5~ were implanted into the tibiae of rabbits for 3 or 8 weeks. Contact microradiography and SEM‐EPMA showed that all three kinds of glass formed a Ca, P‐rich layer in combination with a Si‐rich layer on their surfaces within 3 weeks and formed a direct bond with bone via these layers. The detaching test, performed 8 weeks after implantation, showed that the loads required to detach the implants from the bone were almost equal for the phosphorus‐free and the phosphorus‐containing glasses. It was concluded that even P~2~O~5~‐free CaO · SiO~2~ glass formed a Ca,P‐rich layer on its surface and bonded tightly with living bone. If glasses and glass‐ceramics release at least Ca^2+^ and HSiO~3~^−^ ions, this would be sufficient for them to form the Ca,P‐rich layer on their surfaces in vivo, enabling them to bond directly with bone.