Evaluation of the mechanical stress on root from orthodontic tooth movement by sliding mechanics- a three-dimensional finite element analysis

Abstract

Background and objectives This finite element study was conducted to calculate the distribution of stresses on root surfaces when an orthodontic force of 2N was applied at different degrees namely 0 30 and 45 degrees to the horizontal plane.Methods An in-vitro finite element method was used to construct a three dimensional finite element model of a mandibular arch without first premolars according to values given by Wheelers standard dental anatomy book using ANSYS 12 finite element software. Mechanical properties like Youngs modulus of elasticity and Poissons ratio were assigned to the model. To this model an orthodontic force was applied at various degrees on the crown of the tooth model. After the application of the forces initial stress on the root surface of mandibular anterior teeth was evaluated.Results The greatest amount of the maximum level of stress was found at the cervical margin of the PDL of all the tooth roots while the maximum stresses was highest at the root crest region of the canine. Bodily movement and tipping forces produce stress concentrated at the alveolar crest and not at the root apex.Interpretation and conclusion Clinical implications of this study suggested that if the clinician is concerned about placing an implant as anchorage for sliding mechanics to close dental arch spacethere is the same risk of root resorption after loading of force of 2N at 0 30 and 45 degree from the horizontal level.