Authors: Takashi Kizuki Tomiharu Matsushita Tadashi Kokubo
Publish Date: 2015/01/15
Volume: 26, Issue: 1, Pages: 41-
Abstract
Polyetheretherketone PEEK is widely used in orthopedic implants such as spinal fusion devices because of its moderate elastic modulus as well as relatively high mechanical strength However it does not bond to living bone and hence it needs autograft to be fixed to the bone In this study we attempted to add bonebonding properties to PEEK by coating with TiO2 synthesized by the sol–gel process When a TiO2 sol solution consisting of titanium isopropoxide water ethanol and nitric acid was deposited on a PEEK substrate without any pretreatment the formed TiO2 gel layer was easily peeled off after subsequent treatments However when the same solution was deposited on PEEK that was preliminarily subjected to UV or O2 plasma treatment the deposited TiO2 gel layer strongly adhered to the substrate even after subsequent treatments The strong adhesion was attributed to the interaction among the C–O C=O and O–C=O groups on the PEEK owing to the UV or O2 plasma treatment and the Ti–O bond of the TiO2 gel Apatite did not form on the asformed TiO2 gel layer in a simulated body fluid SBF even within 3 days however apatite formed after soaking in 01 M HCl solution at 80 °C for 24 h This apatite formation was attributed to positive surface charge of the TiO2 gel layer induced by the acid treatment The PEEK with the TiO2 gel layer coating formed by the proposed process is expected to bond to living bone because a positively charged titanium oxide which facilitates the formation of apatite in SBF within a short period is known to bond to living bone
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