Evaluation of the Behavior of Tissue Fluid in the PDL Region during Application of Orthodontic and Physiologic Forces Using 3-dimensional Finite Element Analysis

Abstract

The periodontal ligament (PDL) is a dense connective tissue which surrounds the tooth root and connects it with the alveolar bone. The majority of studies have only evaluated the viscoelastic behavior of the PDL. On the other hand, new technologies and techniques have not to date been used to evaluate the dynamic and three-dimensional behavior of the tissue fluid in the PDL region. The aim of the present study was to determine the behavioral pattern of tissue fluid in the PDL region during application of orthodontic and physiologic forces using 3-dimensional poroelastic finite element analysis. Materials and methods. In the present virtual in vitro study three-dimensional finite element analysis was used. Guinea pig mandible was used as the specimen. Micro CT scan images were prepared from the tooth and its surrounding alveolar bone and then their 3D model was prepared. By defining loading and interfacial conditions, 1-Newton intrusive force was applied to the tooth. Finally, the behavior pattern of the tissue fluid was interpreted. Results. Displacement values for the PDL, alveolar bone and the tooth were 198.7, 28.7 and 143.3 m, respectively. In addition, tension values for the PDL, bone and the tooth were 3.54, 344 and 12.66 Pa, respectively. Conclusion.The bone surrounding the periodontal ligament is not cribriform and is in the form of an accordion. The displacement of PDL is more than that of the tooth. In addition, the displacement of the PDL is once toward the tensile side and once toward the exit side, i.e. toward the cervical area