title: Morphological and chemical characterizations of the interface of a hydroxyapatite-coated implant.
abstract: The present study aimed at morphological and chemical characterization of the coating-substrate interface of a commercially available dental implant coated with plasma-sprayed hydroxyapatite (HA). For this purpose, elements in the chemically and mechanically exposed substrate surfaces were analyzed by EPMA and XPS. A thin titanium oxide film containing Ca and P was found at the interface. When the implant was subjected to mechanical stress, a mixed mode of cohesive and interfacial fractures occurred. The cohesive fracture was due to separation of the oxide film from the substrate, while the interfacial fracture was due to exfoliation of the coating from the oxide film bonded to the substrate. Analysis showed diffusion of Ca into the metal substrate, hence indicating the presence of chemical bond at the interface. However, mechanical interlocking seemed to play the major role in the interfacial bond.
authors.affiliation: Mimura Dental Clinic, Fujinomiya, Shizuoka, Japan.
authors.forename: Kiichirou
authors.initials: K
authors.lastname: Mimura
authors.forename: Kouichi
authors.initials: K
authors.lastname: Watanabe
authors.forename: Seigo
authors.initials: S
authors.lastname: Okawa
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Osamu
authors.initials: O
authors.lastname: Miyakawa
mesh_terms: D002118:Calcium / Q000032:analysis; D002244:Carbon / Q000032:analysis; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D001840:Dental Bonding; D015921:Dental Implants; D003799:Dental Stress Analysis; D004058:Diffusion; D017886:Durapatite; D004577:Electron Probe Microanalysis; D010710:Phosphates / Q000032:analysis; D013052:Spectrometry, X-Ray Emission; D014025:Titanium / Q000032:analysis
chemical_list: D020099:Coated Materials, Biocompatible; D015921:Dental Implants; D010710:Phosphates; C009495:titanium dioxide; D002244:Carbon; D017886:Durapatite; D014025:Titanium; D002118:Calcium