Method for preparing a biomaterial based on hydroxyapatite, resulting biomaterial and surgical or dental use

Abstract

A solid powder product with a Ca/P ratio of between 1.40 and 1.90 is prepared from tricalcium phosphate and tetracalcium phosphate. An aqueous solution containing calcium ions and phosphate ions with a Ca/P ratio higher than 0.20 and lower than 0.50 is prepared. The aqueous solution and the solid powder product and optionally water are mixed to obtain a mixture with a liquid/solid weight ratio of between 0.30 and 0.65 and a resulting paste with a Ca/P ratio of between 1.50 and 1.67.

What is claimed:  
     
         1 . Biomaterial comprising a microcrystalline hydroxy apatite of atomic ratio Ca/P comprised between 1.50 and 1.67, having in combination the following characteristics: 
 substantial compression resistance comprised between 15 and 25 Megapascals,    a solubility corresponding to a solubility product comprised between 10 −94  and 10 −100 ,    and a surface substantially comprised between 20 and 120 m 2 /g.    
     
     
         2 . Surgical or dental set, characterized in that it comprises: 
 a batch of solid pulverulent product comprising a mixture of tricalcium phosphate and tetracalcium phosphate in an atomic ratio Ca/P substantially comprised between 1.40 and 1.90, said batch being packaged in a first closed sterilized container,    a batch of aqueous solution containing calcium ions and phosphate ions in an atomic ratio Ca/P substantially comprised between 0.20 and 0.50, said batch being packaged in a second closed sterilized container,    said batches of solid pulverulent product and of aqueous solution being such that the overall liquid/solid weight ratio is comprised between 0.30 and 0.65 and the overall atomic ratio Ca/P) is between 1.50 and 1.67.    
     
     
         3 . Surgical or dental set according to  claim 2 , in which the batch of solid pulverulent product contains a weight percent of sodium, potassium or calcium glycerophosphate comprised between 5 and 15%.  
     
     
         4 . Surgical set according to  claim 2 , characterized in that it comprises batches corresponding to one, two or four times the following unit quantities: 
 solid pulverulent product containing between 4.2 and 4.5 g of α tricalcium phosphate and between 5.5 and 5.8 g of tetracalcium phosphate, and as the case may be between 1.4 and 1.6 g sodium, potassium, or calcium glycerophosphate,    aqueous solution containing between 0.18 and 0.22 g of calcium hydroxide and between 1.3 and 1.5 g of phosphoric acid, in solution in a 3.8 to 4.2 g of water.    
     
     
         5 . Dental set according to claim 1   2 , characterized in that it comprises batches corresponding to one or two times the following unit quantities: 
 solid pulverulent product containing between 0.42 and 0.45 α tricalcium phosphate and between 0.55 and 0.58 g of tetracalcium phosphate, and as the case may be between 0.14 and 0.16 g of sodium, potassium or calcium glycerophosphate,    aqueous solution containing between 0.02 and 0.025 g of calcium hydroxide and between 0.13 and 0.15 g of phosphoric acid, in solution in 0.3 to 0.4 g of water.