title: Plasma electrolytic oxidation of titanium and improvement in osseointegration.
abstract: Reducing the osseointegration time for biomedical titanium implants in surgical patients is an important goal. However, a huge controversy exists over the effectiveness of osseointegration of the surface layer by plasma electrolytic oxidation (PEO), which is a widely favored surface modification for titanium-based implants. In this study, various surface coatings, including anatase-TiO2 (A-TiO2 ), rutile-TiO2 (R-TiO2 ), hydroxyapatite (HAp), strontium-containing hydroxyapatite (Sr-HAp), and dual-phase HAp-TiO2 were synthesized on titanium implants by PEO. A comparative study of osseointegration performance (both in vitro and in vivo) and bone/implant adhesion strength conducted using push-out thrust tests were demonstrated. The in vitro experimental test results agree strongly with the in vivo test results: the dual-phase HAp-TiO2 coating exhibits the superior cell adhesion and differentiation condition among all of the coatings in the in vitro tests and therefore has the highest push-out bonding strength of 5.37 MPa after 12 wk of implantation in the in vivo test. The HAp-containing coatings benefit from its bioactivity and therefore perform the others in terms of long-term osteocyte growth (from the in vitro results) and the extent of osseointegration (from the in vivo results). The dual-phase HAp-TiO2 coating provides the advantages of both the bioactive HAp and structural enhancement by the TiO2 , effectively promoting osseointegration.
authors.affiliation: Department of Dental Technology and Materials Science, Central Taiwan University of Science and Technology, Taiwan, ROC. cjchung@seed.net.tw
authors.forename: Chi-Jen
authors.initials: CJ
authors.lastname: Chung
authors.forename: Rein-Teng
authors.initials: RT
authors.lastname: Su
authors.forename: Hou-Jen
authors.initials: HJ
authors.lastname: Chu
authors.forename: Hsien-Te
authors.initials: HT
authors.lastname: Chen
authors.forename: Hsi-Kai
authors.initials: HK
authors.lastname: Tsou
authors.forename: Ju-Liang
authors.initials: JL
authors.lastname: He
mesh_terms: D016475:3T3 Cells; D000818:Animals; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D004572:Electrolysis; D008422:Materials Testing; D051379:Mice; D016348:Osseointegration; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism; D010084:Oxidation-Reduction; D058626:Plasma Gases; D019736:Prostheses and Implants; D011817:Rabbits; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D020099:Coated Materials, Biocompatible; D058626:Plasma Gases; C009495:titanium dioxide; D014025:Titanium
keywords: dual-phase HAp-TiO2; hydroxyapatite (HAp); osseointegration; plasma electrolytic oxidation (PEO); strontium-containing hydroxyapatite (Sr-HAp); titanium dioxide (TiO2)