Strength of bonding between A-W glass-ceramic and the surface of bone cortex.

We examined the bonding strength of apatite- and wollastonite-containing glass-ceramics (A-W.GC) to the surface of bone cortex. Semi-column-shaped blocks of A-W.GC were fixed with screws on the surface of the tibiae of rabbits. The blocks of alumina-ceramic were used as the control. The load required to detach the implant from the surface of bone cortex was measured 2, 4, 8, and 25 weeks after the implantation. The bonding strength between A-W.GC and the surface of bone cortex increased with time. It increased remarkably 4 weeks after the implantation, suggesting that the chemical bonding advanced rapidly between 2 and 4 weeks after the implantation. The tensile strength of bonding reached a maximum of 15.1 +/- 3.1 kg/cm2 25 weeks after the implantation. The shear strength of bonding reached a maximum of 17.1 +/- 2.3 kg/cm2 25 weeks after the implantation. From these studies, we conclude that A-W.GC has a capability of making relatively quick bonding to the surface of bone cortex.