[Tricalcium Phosphate as a Bone Tissue Substitute (testing of biological properties in animal experiments.]

The authors present the results of implantations of tricalcium phosphate of LASAK Co. Prague into defects of the long bones of 12 experimental dogs after an exposure time of 2,4 and 8 months. Seven modifications of the mentioned material were used in the form of granules, prisms and powder in a total of 18 implantations. In all instances specimens after implantation were taken which did not have macroscopic or microscopic signs of inflammatory reaction. X-ray did not reveal any clear spots round the material, signalizing an inflammatory of fibrous reaction. Microscopic examination confirmed excellent tolerance of the surrounding live tissue and osteoblastic activity in the immediate vicinity of the implants. After 8 months tricalcium phosphate was still present and only a smaller size of the particles suggested its absorbability. In the discussion the authors mention some possibilities of the clinical use of this material and contemplate on the problem of absorption. Key words: bone defect, tricalcium phosphate, bioactive glass ceramics, osteoinduction, absorbability of material.