Clinical Effect Of Demineralized Auto-tooth Bone Graft In Repairing Distal Bone Defect Of Mandibular Second Molar After Extraction Of Mandibular Impacted Third Molar

Objective:To observe the effect of demineralized autologous dental bone meal combined with guided tissue regeneration on the reconstruction of the distal bone defect of the second mandibular molar after the removal of the impacted third molar,and to compare it with the inorganic bovine bone meal.Methods:Selected from January 2020 to July 2020 in the first hospital of shanxi medical university remoal of mandibular impacted maxillary third molar dental surgery requirements,according to the panoramic piece can be diagnosed with mandibular impacted wisdom teeth in the horizontal or nearly,and adjacent to the second molar teeth in 20 patients with bone defect,age 25 to 35 years old,in conformity with the case study and exclusion criteria,were randomly divided into two groups,Experimental group:DATB group was prepared at the side of the chair immediately after the third mandibular molar was removed and implanted in the tooth extraction socket to repair the distal bone wall defect of the second mandibular molar.The surface was covered with absorbable barrier film in 10 cases.Control group: inorganic bovine bone meal group(ABBM).ABBM was implanted in tooth extraction fossa at the same time after the third mandibular molar extraction to repair the distal bone wall defect of the second mandibular molar.The surface was covered with absorbable barrier membrane in 10 cases.The general condition of the operation area was followed up by telephone on the 1st,3rd and 5th day after the operation.The wound healing was re-examined and sutures were removed on the 10th day after the operation.The changes of the distal probing depth(and attachment loss)of the second mandibular molar were compared between the two groups before and 6 months after operation.The height of bone defect and the change of bone mineral density in the distal middle of mandibular second molar were measured by cone-beam CT before and 6 months after operation.SPSS22.0 was used for statistical analysis and comparison.was revisited 10 days after the operation;the probing depth(PD)and the loss of attachment of the adjacent teeth were compared before and 6 months after the operation.Attachment Loss(AL)changes;cone-beam computed tomography(CBCT)measured the bone defect height and bone density changes of the two groups before and months after the operation,and SPSS22.0 was used for statistical analysis and comparisonResults:1.Telephone follow-up: 1-3 days after operation,20 patients had varying degrees of pain and swelling,the degree of pain was mild,5 days after operation,the operation area of 20 patients returned to normal.10 days after the operation,all patients were healed,no mucosal swelling,infection and rejection.2.Six months after operation,the distal probing depth,attachment loss,bone defect height and bone density of the second molars in the autogenous tooth and bone powder group were significantly improved compared with those before operation,and the difference was statistically significant(P<0.05).3.6 months after operation,the probing depth,attachment loss,bone defect heighand bone density of the second molars in Bio-oss group were significantly improvecompared with those before operation(P<0.05).4.There was no significant difference in the depth of distal probing,attachment loss and bone defect height between the two groups after operation(P>0.05),but the BMD of Bio-oss group was significantly different from that of autogenous tooth and bone powder group(P<0.05).Conclusion:1.After the extraction of impacted mandibular third molar,demineralized autogenous dental bone powder combined with guided tissue regeneration can effectively repair the distal bone defect of mandibular second molar,reduce the depth of periodontal pocket and improve the attachment level.2.Compared with the inorganic bovine bone powder,the demineralized autogenous dental bone powder showed rapid bone remodeling at the same time,fused with the host bone tissue and formed new bone,which reflected the good osteogenesis of autogenous bone and easy tissue fusion.3.After the extraction of impacted mandibular third molar,the effect of demineralized autogenous dental bone powder combined with guided tissue regeneration is better than that of inorganic bovine bone powder in repairing the distal bone defect of mandibular second molar.