Three Dimensional Finite Element Analysis Of Maxillary Central Incisors And Its Clinical Significance In Immediate Implant Placement

Objective: This study was to observe the stress of distribution in three anatomical types of maxillary central incisor and provide reference for the determination of surgical site in immediate implant placement.Methods: CBCT image data were collected from Longgang District Central Hospital of Shen Zhen which conform to the anatomical classification of three different natural maxillary central incisors.Mimics,3 matic,and Ansys software were used to establish three 3-D finite element models of maxillary central incisors and their surrounding alveolar bones.The simulated bite force was applied to the above models with a static load force at five angles of 0°,30°,45°,60°,and 90°.The stress and displacement values at the four lines of the cementoenamel junction(CEJ)– apical labial,palatal,mesial,and distal on the periodontal ligament of the maxillary central incisor.Results: The equivalent stress on the periodontal ligament and the overall tooth displacement were increased with the angle enlargement,and the equivalent stress and displacement at the four lines were also increased.The peaks of the equivalent stress at the four lines were shown at 0.4mm-2.3 mm below the CEJ,and each equivalent stress value generally decreased while approaching the apex.The displacements at the four lines were increased with angle enlargement,The highest value reaching in the neck of the tooth which showing a steep decline within 6mm-7.5 mm below the CEJ,and a gentle change from 8mm to the apex.The effect of the four lines of type ? has the widest and highest peak value of three types of maxillary central incisor.Conclusions: 1.Combined with the different sub classification of tooth anatomical position could provide a biomechanical theoretical basis for the determination of surgery sites in immediate implant placement.2.For the three anatomical types of maxillary central incisor,each equivalent stress was increased with angle enlargement.The peak values of the equivalent stress and the stress distribution of type ? were larger than other two types.By observing the stress of the root and the surrounding tissues of the maxillary central incisors under different loading conditions.