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Poster: 55Effect of Surface Modification on Biomechanical Properties of TitaniumAlloy Ti6Al4VAbstract*Young Wook Lim - Seoul St. Mary's Hospital - Seoul, KoreaYong Sik Kim - Seoul St. Mary's Hospital - Seoul, KoreaSoon Yong Kwon - St. Mary's Hospital - Seoul, KoreaSuk Gu Han - St. Paul's Hospital - Seoul, KoreaDoo Hoon Sun - Sun General Hospital - Daejeon, Korea- - ,*Email: albire00@naver.comA satisfactory clinical outcome in cementless total hip arthroplasty depends on the primarystability for rapid osseointegration. While the geometric design of an implant contributes tomechanical stability, the nature of the implant surface itself is also of critical importance. Thepurpose of this study is to compare implant osseointegration with the following surfacemodifications made to the titanium alloy Ti6Al4V: machined, grit-blasted, acid etched (SLA),and micro-arc oxidation (MAO). Cylindrical Ti6Al4V implants of the same geometry but withthe four different surfaces were tested in vivo in a beagle dog model (femur). The implant –bone shear strength was evaluated by push-out tests undertaken at 24 weeks after insertion intothe femur, and the four different Ti6Al4V surfaces were examined histomorphometrically. Allthe Ti6Al4V implants were well integrated at the time of sacrifice. X-rays revealed that therewas no osteoporosis, bone resorption, or osteolysis around the implant. The mean bone-toimplantcontact percentages were 22.1% for the machined group, 52.7% for the grit-blastedgroup, 61.3% for the SLA group, and 64.5% for the MAO group. The variation in theinterfacial shear strength was statistically significant between the machined group compared tothe grit-blasted, SLA, and MAO groups. The results of the mechanical testing indicated that theMAO and SLA surface treatments have the potential to enhance peri-implant bone healing.Keywords: micro arc oxidation, grit blasting, acid etching, titanium alloyIntroductionThe majority of implants used in orthopedic and dental fields are fabricated from Ti alloys,owing to minimal tissue reaction, strength, and especially acceptable biocompatibility resultingin strong osseointegration with osteoblasts. 1–3 The thermodynamically stable oxide filmnaturally formed on the surface is regarded as the most influential factor for promoting andaccomplishing osseointegration, and surface modifications are known to affect mechanicalbonding with bone tissue. 4–6In orthopaedic surgery, various surface treatments, including grit blasting and hydroxyapatitefile:///E|/ISTA2010-Abstracts.htm[12/7/2011 3:15:47 PM]