Chemical and Heat Treatments for Inducing Bone-Bonding Ability of Ti-6Al-4V Pedicle Screw

Abstract:

Pedicle screw (PS) system using Ti-6Al-4V PSs became popular in spinal instrumentation system. However, they sometimes case loosening and back-out from bone because of their poor bone-bonding ability. In the present study, Ti-6Al-4V alloy was subjected to the acid-heat or calcium-heat treatments that are effective for inducing high capacities of apatite formation and bone bonding on pure Ti. When the alloy was subjected to the acid-heat treatment, a surface layer composed of rutile and anatase TiO₂ enriched with Al and V was produced. Thus the treated alloy was neutrally charged and did not form apatite in a simulated body fluid (SBF) even after 3 day. In contrast, when the alloy was subjected to the Ca-heat treatment, a surface layer composed of calcium titanate, anatase and rutile free from Al and V was produced. The treated alloy formed apatite in SBF within 3 days. When the Ti-6Al-4V PSs subjected to the Ca-heat treatment was implanted into vertebra of beagle dogs, they showed higher bone-bonding ability as well as bone contact area than those without the treatment. This kind of bioactive Ti-6Al-4V PSs might be useful for spinal instrumentation since they could prevent loosening and back-out from bone.

• Periodical: Key Engineering Materials (Volume 631)
• Pages: 225-230
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.631.225
• Online since: November 2014
• Authors: Seiji Yamaguchi*, Koji Akeda, Koichiro Murata, Norihiko Takegami, Mikinobu Goto, Akihiro Sudo, Tomiharu Matsushita, Tadashi Kokubo
• Keywords: Apatite Formation, Bone Bonding, Pedicle Screw, Simulated Body Fluid, Ti6Al4V

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