Effect of platelet rich plasma and fibrin glue on healing of critical size calvarial bone defects

SUMMARYDespite the insufficient number of experimental studies, autologously producedplatelet rich plasma including high amounts of growth factors, introduced to clinical userapidly. Aim of this study is to compare the effects of platelet rich and platelet poor plasma onhealing of critical size bone defects.Bilateral full-thickness critical size bone defects were created in the parietal bones of32 New Zealand type rabbits which had been studied in 4 groups. In Group I (n=8) salinesolution, in Group II (n=8) thrombin solution, in Group III (n=8) platelet poor plasma and inGroup IV (n=8) platelet rich plasma were applied to the created defects before closure. Halfof the rabbits were sacrified at the end of the 4th week and the remainings were sacrificed atthe end of the 16th week after surgery. Radiological defect area measurement results of 0th, 4thand 16th weeks were compared between the groups. In addition, densities of the newly-formedbones at 16th week were studied. Primary and secondary bone trabecule, neovascularization,bone marrow and connective tissue formation were compared between 4th and 16th weekgroups histologically.After radiological examination, more rapid diminish in defect size was observed inGroup III and Group IV than Group I and Group II both in 4th and 16th weeks, but there wasnot a statistically significant difference between Groups III and IV. Newly-formed bonedensities were also found to be higher in these two groups at the end of the 16 weeks. Newbone formation was detected to be more rapid considering histological parameters, in GroupIII and IV at 4th and 16th weeks. But these two groups have shown similar histological resultsexcept for increased secondary bone trabecula at the end of 4th week in group IV.As a result, this study demonstrates that platelet rich plasma and platelet poor plasmamight have favorable effects on bone healing but cannot reveal any difference between thesetwo substances considering osteoinductive potential. In order to determine the differencebetween the beneficial effects of platelet rich and platelet poor plasma, similar studies usingplatelet rich plasma that have higher platelet concentrations are required.