Resorbable bioactive calcium phosphate cement
OwnerSung-Tsuen Liu, Harvey H. Chunginventors
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Abstract
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.
Claims14
A cementitious paste for orthopaedic, dental and maxillofacial applications comprising:
- a cementing powder of tetracalcium phosphate;
- a setting reagent consisting essentially of an acidic citrate, wherein the weight ratio of cementing powder to setting reagent lies between 2:1 and 15:1;
- and
- sufficient water to form said paste, and which paste, after setting has a pH greater than 5.
Dependencies are inferred from the claim text.