title: In vivo evaluation of plasma-sprayed titanium coating after alkali modification.
abstract: In this paper, plasma-sprayed titanium coatings were modified by alkali treatment. The changes in chemical composition and structure of coatings were examined by SEM and AES. The results obtained indicated that a net-like microscopic texture feature, which was full of the interconnected fine porosity, appeared on the surface of alkali-modified titanium coatings. The surface chemical composition was also altered by alkali modification. A sodium titanate compound was formed on the surface of the titanium coating and replaced the native passivating oxide layer. Its thickness was measured as about 150 nm which was about 10 times of that of the as-sprayed coating. The bone bonding ability of titanium coatings were investigated using a canine model. The histological examination and SEM observation demonstrated that more new bone was formed on the surface of alkali-modified implants and grew more rapidly into the porosity. The alkali-modified implants were found to appose directly to the surrounding bone. In contrast, a gap was observed at the interface between the as-sprayed implants and bone. The push-out test showed that alkali-modified implants had a higher shear strength than as-sprayed implants after 1 month of implantation. An interfacial layer, containing Ti, Ca and P, was found to form at the interface between bone and the alkali-modified implant by EDS analysis.
authors.affiliation: Plasma Spray Laboratory, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi road, Shanghai 200050, People's Republic of China. xueweichang@163.com
authors.forename: Weichang
authors.initials: W
authors.lastname: Xue
authors.forename: Xuanyong
authors.initials: X
authors.lastname: Liu
authors.forename: XueBin
authors.initials: X
authors.lastname: Zheng
authors.forename: Chuanxian
authors.initials: C
authors.lastname: Ding
mesh_terms: D000497:Alloys; D000818:Animals; D018786:Bone Substitutes / Q000737:chemistry*; D001842:Bone and Bones / Q000378:metabolism; D002118:Calcium / Q000737:chemistry; D002130:Calcium Phosphates / Q000737:chemistry; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D004285:Dogs; D005269:Femur / Q000378:metabolism; D017102:Fracture Healing; D006882:Hydroxyapatites / Q000737:chemistry; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D016348:Osseointegration; D010087:Oxides / Q000737:chemistry; D010758:Phosphorus / Q000737:chemistry; D019736:Prostheses and Implants; D013054:Spectrophotometry, Atomic; D013499:Surface Properties; D013997:Time Factors; D014025:Titanium / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000497:Alloys; D018786:Bone Substitutes; D002130:Calcium Phosphates; D020099:Coated Materials, Biocompatible; D006882:Hydroxyapatites; D010087:Oxides; C471701:sodium titanate; C031462:titanium alloy (TiAl6V4); C009495:titanium dioxide; D010758:Phosphorus; D014025:Titanium; D002118:Calcium