In previous studies, it has been shown that both simvastatin (chlolesterollowering drug) and platelet-rich plasma (PRP) were capable of promoting bone formation. The aim of this study was to compare the effects of PRP and simvastatin on healing of critical-size bone defects.Methods:
A total of 33 rats (3 for PRP preparation) were used in the experiment. Critical-size defect 8-mm diameter was created in 30 rats’ calvarium. Rats were divided into 3 groups. Each group contained 10 animals. In Group A the defect was filled with phosphate-buffered saline only, in Group B with 0.5 mL PRP, and in Group C with 0.1 mg simvastatin. The defects were evaluated by radiographic analysis at 8th and 16th weeks. The animals were sacrificed 16 weeks after the surgery. Histological examination was performed to assess the new bone-forming area. Vessels, fibroblasts, osteoblasts, and osteoclasts were marked in 524749.1-μm2 area and counted with using Clemex Vision Lite 3.5 Image Analysis program. The results were statistically analyzed.