Enhancement of bone bonding strengths of titanium alloys by alkali and heat treatments

摘要

The purpose of this study is to investigate whether alkali-and heat-treated titanium alloys can bond to bone. Surface-smoothed rectangular plates of Ti6Al4V, Ti6Al2Nb1Ta, and Ti15Mo5Zr3Al were prepared. The alkali-and heat-treated and untreated each alloy implants were implanted into proximal tibiae of mature rabbits, treated implant for right side and untreated for left. At 8 and 16 weeks after operation detaching test and histological examination were performed. Untreated implants showed almost no bonding even at the 16 weeks after implantation. In contrast treated implants showed bonding to bone both at 8 and 16 weeks. Histological examination showed that alkali-and heat-treated alloys bonded to bone directly. On the other hand untreated implants had intervening fibrous tissue between bone and plate. Although in this study even tentative conditions of treatments enhance bonding strength of titanium alloys, the most suitable conditions of treatments for highest bonding strength should be determined by further experiments. These new bioactive titanium alloys are supposed to be available for weight-bearing and bone-onding orthopaedic devices.