ORIGINAL ARTICLE The effect of hierarchical micro/nanosurface titanium implant on osseointegration in ovariectomized sheep J. Xiao & H. Zhou & L. Zhao & Y. Sun & S. Guan & B. Liu & L. Kong Received: 24 June 2010 / Accepted: 25 August 2010 / Published online: 29 September 2010 # International Osteoporosis Foundation and National Osteoporosis Foundation 2010 Abstract Summary Hydrofluoric etching and anodized hierarchical micro/nanotextured surface titanium implant was placed in mandibles of ovariectomized sheep for 12 weeks, and it showed improved osseointegration by resonance frequency analysis (RFA), microcomputed tomography (micro-CT) evaluation, histomorphometry, and biomechanical test. Introduction This study aimed to investigate the effects of micro/nanotextured titanium implant on osseointegration in ovariectomized (OVX) sheep. Methods The hierarchical micro/nanotextured surface of titanium implant was fabricated by acid in 0.5% (w/v) hydrofluoric (HF) and anodized in HF acid electrolytes with a DC power of 20 V, and the machined surface implants with no treatment served as control group. The implants were placed in mandibles of OVX sheep, respectively. Twelve weeks after implantation, RFA, microcomputed tomography, histomorphometry, and bio- mechanical tests were applied to detect the osseointegra- tion of the two groups. Results The implant stability quotient (ISQ) values, the maximum pull-out forces, and the bone–implant contact (BIC) were 65.5±6.3, 490.6±72.7 N, and 58.31±5.79% in the micro/nanogroup and 58.3±8.9, 394.5±54.5 N, and 46.85±5.04% in the control group, respectively. There was no significant difference between the two groups in ISQ values (p >0.05), but in the micro/nanogroup, the maximal pull-out force and the BIC were increased signifi- cantly (p <0.05 or p <0.01). Micro-CT analysis showed that the bone volume ratio and the trabecular number increased significantly (p <0.01), and the trabecular separation de- creased significantly (p <0.05) in the micro/nanogroup. Conclusion Implant modification by HF acid etching and anodization to form a hierarchical micro/nanotextured surface could improve titanium implant osseointegration in OVX sheep 12 weeks after implantation. Keywords Anodization . Dental implant . Hydrofluoric etching . Micro/nanotexture . Osteoporosis . Surface modification Introduction Prosthetic treatment with titanium implant has brought comfort and esthetic results to patients and therefore earned a favorable reputation from both patients and dentists [1]. Jianrui Xiao and Hong Zhou equally contributed to this study. J. Xiao : H. Zhou : B. Liu (*) : L. Kong (*) Department of Oral and Maxillofacial Surgery, School of Stomatology, The Fourth Military Medical University, 145 West Changle Rd, Xi’ an 710032, People’ s Republic of China e-mail: implant@fmmu.edu.cn L. Kong e-mail: kongliang@fmmu.edu.cn J. Xiao e-mail: xiaojianrui@gmail.com J. Xiao : L. Zhao Department of Stomatology, PLA 252 Hospital, Baoding 071000( Hebei Province, People’ s Republic of China Y. Sun : S. Guan Department of Medical and Education, School of Stomatology, The Fourth Military Medical University, Xi’an 710072, People’ s Republic of China Osteoporos Int (2011) 22:1907–1913 DOI 10.1007/s00198-010-1413-0