Enhancement of Early Osseointgration by Coating TiO2 Nanotubes with Annealed Fishbone(In Vivo Study)

Abstract

New method was used to accelerate bone osseointegration, milled and annealed fishbone was used as coating layer on Ti-6Al-4V alloy after creating TiO₂nanotube(TNTs) on it. Mechanical and thermal treatments were used to extract natural Hydroxyapatite (HAp) from fishbone.After milling, fish bones were heated at different temperatures. Annealed fish bones at 900⁰C had correspondence structure to that of standard one as X-ray diffraction (XRD) confirmed.  After creation TNTs on screws which were made from Ti-6Al-4V alloy, EPD was used to coat them with milled fishbone, annealed fishbone and commercial HAp. All screws were implanted inside the tibia of white New Zealand rabbits to evaluate the biocompatibility of modified alloys and to assess the clinical success of implants. Radiographic and histologic evaluations showed that implants with double surface modifications illustrate new bone formation around them. These results refer to the success of all surface modifications in this work , however the comparison between them illustrate superiority of coating by annealed fishbone over the other coating. During implantation interval from 4 to 12 weeks, screws with double surface modifications (creating TNTs and then coating with annealed fishbone) had highest removal torque (RTQ) values i.e. highest osseointegration acceleration rate. After 12 weeks of implantation, torque values for screws coated with commercial HAp are approximately equal to those values associated with screws coated with annealed fishbone.

Keywords:Ossseointegration,Titaniumimplants,Hydroxyapatite, TiO₂Nanotube,Fishbone.