The effects of platelet rich plasma on bone growth in peri-implant defects

ABSTRACT

methods have been used to fill in the defects around the implants. Recently, researchs of developing and purifying various growth factors, and efforts to apply these growth factors in clinical situations have been carried out. Among those tries, platelet-rich plasma(PRP) containing abundant PDGF and TGF-beta obtained by the sequestration and concentration of platelets by the gradient density centrifugation became one of the popular and preferred methods becuase of relatively simple procedure and abundant growth factor components. Bone morphogenic protein(BMP), platelet-derived growth factor(PDGF), and transforming growth factor-beta(TGF-beta) are growth factors in the PRP that promote the bone formation. To elucidate the effects of PRP on the bone formation in peri-implant bone defects, twenty-seven Steri- Oss implants were inserted in the mandibular premolar areas of 8 adult dogs and artificial bone defects(3x4x4mm) were prepared at the buccal side of the implants in 1st premolar, at the distal side of the implants in 3rd premolar. The control groups were filled with bovine bone grafts without PRP, and the experimental groups were filled with bovine bone grafts with PRP. Animals were sacrificed at 1, 2, 4, 8, and 12 weeks after the operation and speimens were observed by light and electron microscope. The results were as follows. first, the bone formation was observed at 1st week in the experimental groups,but at 2nd week in the control groups. second, the mature bone was observed at 4th week in the experimental groups, but 8th week in the control groups. the bone growth rate of experimental groups was more rapid than that of control groups. third, at 12th week, bone density ratio was higher in the experimental groups(71.65%) than that of the control groups(48.49%). fourth, Grafted bovine bone were almost completely absorbed at 1st week in experimental groups, but it was still present at 8th week in control groups. From the above results, PRP may accelerate the formation of new bone by promoting absorption of the graft material and increasing the growth rate of bone.