The Three Dimensional Finite Element Research On Bonding Quality Under The Effect Of Orthodontic Racketstructure And Its Area

Objective: To establish the 3-D finite element model under the condition of different orthodontic bracket structures and areas. Compare the effects of different condition to the bonding quality, analysis the advantages and disadvantages of different bonding methods in order to provide a theoretical basis and reference to the clinic treatment, production, and experimental research.Method: The groove bracket,grid bracket and inclined grid bracket and different areas are selected respectively to establish the finite element model of tooth-binder-bracket system, combining with the CT graph and the average measured tooth data of Chinese people. The tensile force, shear force and twist force are applied to the system to analysis the variation features of stress and displacement on different loading method, compare the effect of different bracket structures and areas to the bonding quality of the system.Results: 1. 15 types of 3-D finite element models of different bracket structures and areas are established in the experiment. 2. The distribution of max principle stress and Von-mises stress in the system are heterogeneous. 3. The max stress in the system appears when tension force is applied and min stress appears when twist force is applied. 4. The shear performance increases with the increasing of bracket length the tension and twist performance reach to the optimal when the length and width are almost the same. 5.Grip Bracket system has the min stress but the max displacement.Conclusions: 1.Tension force can easily lead to bonding failure with single loading. 2.The experiment shows that the bonding strength rises with the increasing of bracket areas. 3.The grip bracket system has the best bonding performance when the conditions are the same.