Histomorphometric and Densitometric Evaluation of the Effects of Platelet-Rich Plasma on the Remodeling of β-Tricalcium Phosphate in Beagle Dogs

Abstract
Countless possibilities are available in maxillofacial surgery for the filling of bone defects. The best bone substitute known at present is osteogenic autogenous bone, but its use is accompanied by numerous disadvantages. The question has arisen of whether results attained with osteoconductive bone substitutes approach those achieved by the transplantation of autogenous bone. The aims of the investigation were to measure the effects in animal experiments of the growth factors to be found in the platelets on the rate of remodeling of β-tricalcium phosphate, and on the quality of the new bone formed. Defects formed in the mandibles of 10 Beagle dogs were filled with β-tricalcium phosphate or with a mixture of β-tricalcium phosphate and platelet-rich plasma obtained from autogenous blood. The quality of the hard tissue formed and the effect of the platelet-rich plasma were examined by statistical analysis of the densitometric results obtained after 6 weeks and the histological and histomorphometric results obtained after 12 weeks. The densitometric study revealed that the bone formation was significantly more effective when platelet-rich plasma was used; at this stage, histomorphometric evaluation did not indicate a significant difference. After 12 weeks, however, the histomorphometric study demonstrated a significant difference in favor of the bone substitute used together with platelet-rich plasma. The results strongly suggest that use of the platelet-rich plasma suspension accelerates the remodeling of β-tricalcium phosphate and leads to the formation of hard tissue with a quality similar to that of the autogenous bone.