Abstract: Objective　To observe and compare the curative effect and difference of PRP combined allograft bone powder and autogenous iliac bone graft in the treatment of maxillofacial bone defect. Methods: 22 patients with maxillary lateral incisor and canine area of missing teeth and bone defect were randomly divided into A group and B group, 11cases in each. The two groups were treated with PRP combined with allograft bone powder or autogenous iliac bone graft to fill the bone defect area. Based on the CT data, the original defect area were evaluated in 1 months, 2 months and 3 months after the operation. Compared to the normal bone, the changes of bone growth in the filling area were measured. During the second dental implant operation, the bone was taken for pathological analysis, the bone quality was evaluated, and the ISQ value of the implant was measured. The initial stability of the implant was evaluated, and the grasping ability and biomechanics of the new bone to the implant were assessed. Results: Based on the precondition that the baseline data were comparable, in group A and B, the CT value was not statistically significant at all observation points after bone grafting operation(P > 0.05). The new bone CT value of group A was higher than the normal bone(P < 0.05),while the CT value of group B had no significant difference (P > 0.05).The ISQ value, which means initial stability of implants, had no significant difference between the two groups. New bone biopsy showed complex new bone and fibrous tissue with granular calcification in group A, but good quality cancellous bone with very few fibrous tissue and calcified impurities in group B. Conclusion: PRP combined with allograft bone filling bone defects can avoid extra invasive operation and surgical incision, more easily accepted by clinical treatment. Autogenous iliac bone graft has better biocompatibility and bone growth. Two methods of bone in dental implant both reflect good biomechanical properties and do not affect the initial stability of implants. PRP combined with allograft bone powder or autogenous iliac bone graft is selected according to the indications and clinical practice.

Key words: Platelet-rich plasma (PRP), autograft of iliac bone, bone defect of jaw, dental implant