Finite Element Analysis on the Orthodontic Treatment of Loose Tooth with Overlapping by Periodontal Splint

In this study, two different fixation methods, strong fiber + flow resin adhesive splint and Super-bond adhesive splint, were used to treat the second degree of loose tooth, and finite element simulation was performed. The mechanical changes of periodontal ligament were analyzed by applying the same load but different angles to the loose tooth. Conclusions: the periodontal ligament stress will increase sharply about 5.126 MPa - 43.43 MPa if the treatment is not taken when the tooth has 11 degree loose with 2 mm overlap. The mechanical states of periodontal ligament are different in different loading angles and different locations under 25N loading. The max Von Mises stress of the periodontal ligament and the max displacement of the teeth increase linearly with the loading angle in the same position, which indicates that the reasonable occlusal angle during the daily chew is more conducive to the treatment of periodontal disease. The fiber splint reduces the displacement of the loosed tooth by about 72.30% - 91.12%, and the maximum stress decreases by 1.808 MPa - 38.275 MPa. The Super-bond adhesive splint reduces the displacement of the loosed tooth by about 78.88% - 92.20%, and the maximum stress decreases by 2.878 MPa - 38.637 MPa. The results show that in the reduce stress of the periodontal ligament or limit the displacement of the loosed tooth after repaired by the two kinds of splints, which repair effects are very obvious, but Super-bond adhesive splint is better.