Effects Of Two Materials On Restoration Of Defect Cavity After Extraction Of Impacted Mandibular Teeth

Objective:To compare the effect of platelet-rich fibrin(PRF)and medical collagen sponge on the repair of the defect cavity after the extraction of mandibular impacted third molar,and observe the effect of two materials on reducing the postoperative reaction and promoting the healing of soft and hard tissue.To provide a clinical reference for the selection of filling materials for cavity defect after tooth extraction.Methods:From November 2016 to October 2017,80 patients with mandibular impacted third molar were removed from Department of Stomatology,Affiliated Hospital of YouJiang Medical University For Nationalities,were selected.A total of 97 mandibular proximal or horizontal non-high resistance of the impacted third molar teeth.They are allocated to three treatment groups randomly:PRF group,collagen group,blood clot group.All patients were treated with the same group of medical staff for minimally invasive extraction under aseptic operation,After the operation,the debridement was treated and filled with fresh blood.In the group PRF,the PRF membrane was filled in the tooth extraction and the collagen group was built into the whole collagen sponge in the tooth extraction,and the blood clot group was filled with fresh blood..After the operation,the pain was recorded in 24 hours,and the mucosa,color,swelling and bleeding were observed on the 7 day after the operation.And shoot digital orthopantomography immediately after operation,6 weeks after surgery,after 12 weeks(Digital Panoranic,radiography,DPR),were the alveolar bone density measurement and mandibular second molars in measuring alveolar bone height,in order to evaluate the soft tissue of two materials after extraction reaction,mucous membrane,healing effect of early healing of alveolar bone.Results:(1)General observation:in group PRF,the soft and hard tissue healed well,no infection,and the formation of pus.After 1 months of collagen group and blood clot group,there were 1 cases of distal periodontium abscess in second molar teeth.(2)There was no statistical difference between the three groups(group of blood clot,collagen group and group PRF)in the grade of 24h pain.(x~2=6.23,P=0.18>0.05).(3)On the 7 day after operation,the color and swelling of mucosa in the three groups(blood clotting group,collagen group and PRF group)had significant difference.(P<0.05),and the level of PRF group was lower than that of blood clotting group.There was no significant difference between the group PRF and the collagen group,the collagen group and the blood clots group.There was no significant difference between the three groups(group of blood clot,collagen group and PRF group)on the 7 day after operation(x~2=6.01,P=0.32>0.05).(4)There was no significant difference in bone density(height)and bone density(height)6 weeks after operation between the three groups(blood clotting group,collagen group and PRF group)(P>0.05),but there was a significant difference in bone density(three)between 12 groups(P<0.05)after 12 weeks.Bone mineral density at 12 weeks after operation:group PRF was larger than that of blood clot.There was no significant difference between group PRF and collagen group,collagen group and blood clot group.The bone height at 12 weeks after operation:PRF group was smaller than that of blood clotting group and collagen group.There was no significant difference between collagen group and blood clotting group.It indirectly indicated that the height of distal alveolar ridge of second molar in PRF group was significantly higher than that in blood clotting group and collagen group.(5)There were significant differences in bone mineral density between three groups(blood clotting group,collagen group,PRF group)at0-6 weeks,6-12 weeks after operation and 0-12 weeks after operation(P<0.05).After 0-6weeks,changes in bone mineral density values of PRF group and collagen group were higher than blood clot group,there was no significant difference between PRF group and collagen group;6-12 weeks after surgery,0-12 weeks after the changes of bone mineral density values in the PRF group than in collagen group and blood clot group,collagen group than blood clot group.(6)There were significant differences in bone height between three groups(blood clotting group,collagen group,PRF group)at 0-6 weeks,6-12 weeks after operation and 0-12weeks after operation(P<0.05).After 0-6 weeks,0-12 weeks after operation,the changes of bone height values in PRF group than collagen group and blood clot group,collagen group than blood clot group;after 6-12 weeks,the changes of bone height values in PRF group than collagen group and blood clot group,collagen group and blood clot group have no significant difference.Conclusion:(1)PRF and collagen sponge can reduce the early side effects of inflammation after extraction and promote the healing of soft tissue in tooth extraction,but the effect of PRF is more significant.(2)PRF and collagen sponge can promote the healing of lacunar bone tissue after tooth extraction.Early two effects are equal,and later PRF promotes more obvious effect.(3)PRF and collagen sponge can reduce the loss of alveolar bone in the second molar,but the effect of PRF is more significant,and has the advantage of first and then slow.