Holistic force-displacement behavior of porcine periodontal ligament—numerical simulation and in-vitro experiment

Abstract

In recent years, orthodontic treatments have become increasingly popular. In these treatments, orthodontic forces, which cause the absorption and deposition of alveolar bone, are applied through brackets and teeth in order to move the teeth to the expected position. The periodontal ligament (PDL) has a determinative role in dental biomechanics; however, the difficulty of predicting PDL behavior has limited the advancement of dental biomechanics. Therefore, this study intends to measure the biomechanical behavior of the PDL and then develop an analytical model to predict the holistic force-displacement relationship of the tooth. In this study, a porcine premolar, including the tooth, periodontal ligament, and alveolar bone, was harvested for experimental purposes. A custom-made apparatus was designed to measure the force-displacement relationship of the PDL. Three analytical models, including linear, exponential, and power functions, were adapted to fit the experimental results. In addition, three-dimensional finite element models were constructed from micro-CT sectional images, and the hyperelastic behavior (Mooney-Rilvin equation) of the PDL was simulated. The results showed that the PDL exhibited nonlinear biomechanical behavior. The power function was found to be a good fit for the force-displacement relationship of the PDL. Furthermore, it was found that the hyperelastic model could predict the biomechanical behavior of the PDL for tension less and equal to 20 N.

Keywords

• periodontal ligament
• force-displacement behavior
• analytical model
• hyperelastic
• finite element analysis