Bone bonding behavior of titanium and its alloys when coated with titanium oxide (TiO2) and titanium silicate (Ti5Si3)

✍ Scribed by Kitsugi, Toshiaki ;Nakamura, Takashi ;Oka, Masanori ;Yan, Wei-Qi ;Goto, Tatsuya ;Shibuya, Takehiro ;Kokubo, Tadashi ;Miyaji, Shiro

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 814 KB
• Volume: 32
• Category: Article
• ISSN: 0021-9304
• DOI: 10.1002/(sici)1097-4636(199610)32:2<149::aid-jbm1>3.0.co;2-t

✦ Synopsis

It has been proposed that the essential requirement for artificial materials to bond to living bone is the formation of bonelike apatite on their surfaces in the body. Recent studies have shown that titanium hydrogel and silica gel induce apatite formation on their surface in a simulated body fluid. In this study, the influence of titanium oxide and titanium silicate on the bonding of titanium alloys to bone was studied. Rectangular implants (15 X 10 X 2.2 mm) of titanium, Ti-6Al-4V, Ti-bAl-2Nb-Ta, Ti-6Al-4V coated with TiO,, and Ti-6A1-4V coated withTi& were implanted into the tibia1 metaphyses of mature rabbits. At 8 and 24 weeks after implantation, the tibiae containing the implants were dissected out and subjected to a detaching testing. The failure load for titanium, Ti-6Al-4V, Ti-6Al-ZNb-Ta, Ti-6A1-4V coated with TiOz, and Ti-6A1-4V coated with Ti& were, respectively, 0.68 ? 0.48, 0.22 -t 0.46, 0.67 * 0.59, 2.18 2 0.71 and 2.03 ? 0.41 kgf at 8 weeks, and 2.7 * 0.91, 2.58 * 1.29, 2.38 ? 0.41, 3.79 ? 1.7, and 2.79 ? 0.87 kgf at 24 weeks after implantation. Histological examination by Giemsa surface staining, CMR, and SEM-EPMA revealed the coated titanium alloy implants directly bonded to bone tissue during early implantation. A Ca-P layer was observed at the interface of the coated implants and the bone. The results of this study indicated that TiOz and Ti&, can enhance the early bonding of titanium alloys to bone by inducing a Ca-P layer (chemical apatite) on the surface of titanium alloys. It also is suggested that the direct bone contact occurs in relation to the calcium and phosphorus adsorption onto the surface of the titanium passive layer formed during long-term implantation.