Effect Of Autogenous Bone Combined With Platelet-rich Fibrin Grafting For The Second Molar Osseous Defect After Impacted Mandibular Third Molar Extraction

Objective:This trial was aimed to explore the therapeutic effect of autogenous bone combined with platelet-rich fibrin(PRF)for distal bone defect of second molar after extraction of impacted mandibular third molar.Methods:A total of 20 patients,aged 25-45 years old,who were admitted to the Oral Multidisciplinary Center of the first hospital of Shanxi medical university from January2019 to July 2019.Both of them were middle or low level impacted teeth with the depth of distant periodontal bone defects adjacent to the second molars ≥ 4mm.controlled randomized.One side as the experimental group: using piezosurgical device and highspeed rotary handpiece minimally invasive extraction,in the same period the removed retromolar pad autogenous alveolar bone was grinded to particles and mixed PRF gel grafted to the distal osseous defect of second molar,then covering PRF membrane.The other side was the control group: removal at intervals of one week.The swelling,pain and restriction of mouth opening of the two groups were compared after 3days’ visit.The probing depth,attachment loss of the second molar was compared before and after 6 months.The difference of bone defect height before and 6 months after the operation was compared by cone-beam computed tomography(CBCT)and SPSS20.0was used for statistical analysis.Results:1.After 3 days pain 3.30±0.87 score and swelling 3.83±0.37 cm in the experimental group was significantly reduced compared with the control group(4.70±1.30 score and 4.05±0.24cm)(P<0.05).2.Six months after the operation,the probing depth of the second molars in the control group was significantly reduced compared with that before the treatment(P<0.05),and there was no significant reduction in the attachment loss and height of bone defect(P >0.05).3.The probing depth,loss of attachment and height of bone defect of the second molar in the experimental group were significantly reduced compared with those before surgery(P <0.05).4.Six months after the operation,the height of the distal attachment loss and bone defect and the central probing depth of the second molar in the experimental group were significantly reduced compared with the control group,with statistically significant differences(P <0.05).There was no significant difference in the depth of distal cheek and distal tongue between the two groups(P >0.05).Conclusion:1.Three days after the operation,the pain and swelling in the experimental group were significantly reduced compared with the control group,suggesting that PRF can significantly reduce the inflammation of early tooth extraction fossa.2.Autogenous bone and PRF transplantation at the same time after impacted mandibular third molar extraction can obviously improved the distal bone defect of the second molar.