Effect of non linearity of PDL on a restored tooth.

To obtain an accurate stress distribution pattern of the restored tooth, taking into account non linear properties of Periodontal Ligament (PDL), linear stress and deformation analysis was carried out with four posts, different in constitution and shape. However, as the PDL exhibits non linear behaviour, more accurate results could be expected by simulating the model for non linear properties of PDL. Due to computational difficulties, a simplified model was prepared and non linear stress analysis was carried out. In case of non linear analysis the stresses were decreased by 25% and deformation was increased by 50% approximately as compared to linear static analysis of the restored maxillary central incisor.