The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 16, 1998
Filed:
Oct. 30, 1997
Sydney M Pugh, Glenburnie, CA;
Timothy J Smith, Kingston, CA;
Millenium Biologix Inc., Ontario, CA;
Abstract
An improved process for producing a thin film of calcium phosphate entities to support bone cell activity thereon. The material to be sintered is prepared by combining a solution of ammonium phosphate with a solution of calcium nitrate to form a sol-gel containing hydroxyapatite. A film of the sol gel is applied to at least one side of the substrate and the film coated on the substrate is sintered to form a solid film of calcium phosphate entities. The improvement in the process comprising sintering the film at temperatures selected from a range of temperatures which optimize a composition of calcium phosphate entities in the film. The sintering step converts hydroxyapatite to .alpha.-tricalcium phosphate where extent of such conversion is temperature dependent. The optimized composition comprises a ratio of hydroxyapatite to .alpha.-tricalcium phosphate in the range of 50:50 to 20:80. A sintering temperature is selected to provide these ratios. The sintering temperature is selected from a range of 920.degree. C. up to 1100.degree. C. where the higher the select temperature, the greater the amount of .alpha.-tricalcium phosphate in the ratio.