RESUMEN
Calcium and Phosphorus are the basic elements in making the inorganic matrix of bone tissue. With the purpose of our research was to study the local effect of hydoxypatite and Platelet Rich Plasma (P.R.P.) on the course of reparative osteogenesis. We used hydroxyapatite granules made by the firm "Polystom" with the chemical formula Ca(10)(PO(4))(6)(OH)(2). Platelet Rich Plasma we have got from blood of rabbits by centrifuging. Experiment was made on 30 rabbits. by operation the standard defects were created with the diameter of 66mm and the depth of 4-5mm on the mandibular bone of the rabbits. In the laboratory group defects were filled with hydroxyapatite and P.R.P., in control group with their own blood. After 7,14,21,35 and 50 days after operation three rabbits were taken from each group. Mandibular bone fractions with defects were relieved from soft tissue, were fixed in 10% neutral formalin and were stained with hematoxyn-eozine. The study showed that in the study group at the initial stage of differentiation from the moment of traumatization the pre-osteoblast and osteoblast contour permanently appears. And in the control group the resorbtion processes were clearly expressed. At the end of the experiment of 50 days in the experimental group the compaction of osteogenic structure was observed in all defect areas. Newly generated tissue underwent compaction. The results of the experiment prove that the hydroxypatite and Platelet Rich Plasma has a stimulative role in the process of osteogenesis. Activation of the reparative processes is far more intensive at the final stage of osteogenesis.