Other

Harvey H Chung

Sung-Tsuen Liu

This invention provides new inorganic composite materials for hard tissue replacement. The new composite material comprises solid material of calcium sulfate which is fully or partially converted to calcium phosphate from aqueous solution. This composite material has good biocompatibility and controllable resorption, and will be very useful for bone substitute material in orthopaedic and dental applications. The fully converted material which comprises mainly apatite calcium phosphate is also useful for chromatography application. A process to prepare these new composite materials is also described.

Calcium phosphate calcium sulfate composite implant material

A surgical cement of high biocompatibility, useful in orthopedic, maxillofacial and dental applications, comprising a calcium alkali phosphate cement with relatively high surface pH of about 7 or higher, and having a wide variety of chemical compositions, permitting flexibility in controlling the bioresorption rate by changing the chemical composition of the cementing powder.

Resorbable bioactive phosphate containing cements

This invention provides a calcium phosphate cement with relatively high surface pH which is very beneficial from the biocompatibility point of view. When calcium phosphate salts react with an acidic reagent to form cement, it normally involves the dissolution and recrystallization process. The acidity of the setting cements depends strongly on the nature of the calcium phosphate salt used, the acidity of the setting reagent, and the reaction rate. The present invention uses high alkaline calcium phosphate ceramics such as tetracalcium phosphate alone or together with calcium phosphate ceramics such as .alpha.-tricalcium phosphate as base cementing powder to increase the surface pH of the setting cement.

Resorbable bioactive calcium phosphate cement

A method for decreasing the dissolution rate of a hydroxyapatite coating or other calcium phosphate coating formed on a metal substrate by treating the coated metal substrate in a fluoride ion containing solution. The effective reagents for fluoride treatment can be any solution which supplies fluoride ion with the suitable pH of the solution being 3 or higher, preferably 5 or higher. The treatment enhances the stability of the coating strength.

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Rancho Palos Verdes, CA, United States of America

Harvey H Chung