This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Yoshinari, M. Articles by Derand, T. Search for Related Content PubMed PubMed Citation Articles by Yoshinari, M. Articles by Derand, T. Pubmed/NCBI databases Compound via MeSH Substance via MeSH Hazardous Substances DB CALCIUM BIS(DIHYDROGEN PHOSPHATE) CALCIUM HYDROGEN PHOSPHATE TITANIUM Social Bookmarking                         What's this?

Solubility Control of Thin Calcium-phosphate Coating with Rapid Heating

Department of Dental Materials Science and Oral Health Science Center, Tokyo Dental College, 1-2-2, Masago, Mihama-ku, Chiba 261, Japan

Y. Watanabe

Department of Dental Materials Science and Oral Health Science Center, Tokyo Dental College, 1-2-2, Masago, Mihama-ku, Chiba 261, Japan

Y. Ohtsuka

Institute for Super Materials, ULVAC JAPAN Ltd., 5-9-7 Toukodai, Tsukuba-city 300-26, Japan

T. Derand

Department of Oral Technology, Faculty of Dentistry, University of Lund, Carl Gustafs vag 34, S 214-21 Malmo, Swede

The thin calcium-phosphate (Ca-P) coatings produced by the ion-beam-mixing method instead of the plasma-spraying method have been found to be amorphous, resulting in films that easily dissolved in simulated body fluid. These coatings crystalized with conventional heat treatment in an electric furnace but tended to crack easily. Therefore, the purpose of this study was to find a suitable heat treatment that controls the solubility of Ca-P coatings without weakening their adhesion to titanium (Ti) substrate. Thin coatings (approximately 1 µm) were coated onto Ti substrates, followed by heat treatment in a conventional furnace and rapid heating by infrared radiation and laser radiation. X-ray diffraction analysis revealed untreated films to be amorphous but to become crystalline after being heated in a furnace at 500°C, heated rapidly with infrared radiation higher than 600°C and with laser radiation at output power of 10W. We evaluated solubility by estimating the film thickness after immersion in simulated body fluid for 5 weeks: Untreated films dissolved within 1 day. Coatings treated with infrared radiation at 600°C dissolved minimally. Cracks were observed in coatings subjected to infrared radiation at 800°C and furnace-heated at 500°C. Coatings treated with laser radiation tended to dissolve easily, with non-uniform surface degradation. X-ray photoelectron spectroscopy analysis at the interface between the coating and the Ti substrate showed that cracks were the result of decreased Ca-implanted layers and too much growth of Ti-P compounds. No difference was recognized in the Ti-oxidation state among specimens. These data indicate that rapid, homogeneous, and comparatively low-temperature heating, such as defocused infrared radiation, controls Ca-P solubility and ensures the adherence of the coatings to the substrate.

Key Words: implant • calcium phosphate • laser radiation • infrared radiation • solubility.

Journal of Dental Research, Vol. 76, No. 8, 1485-1494 (1997)
DOI: 10.1177/00220345970760081101


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?