The Influence Of Micro-implant Insertion Angle And Pull Angle On The Stability Of Micro-implant

Object:Micro-implant because of its simple, minimally invasive, high efficiency and other advantages by a wide range of orthodontic doctor's favor. In order to provide theoretical basis for stability of micro-implant and theoretical basis for clinical use of micro-implant to better, using three-dimensional finite element method to built the three-dimensional finite element model of part of maxillary with micro-implant and analysis the effects of stress distribution of micro-implant-bone interface by implantation angle and load power angle.Method:1. Choose a normal adult as a volunteer, Scan the maxillary and maxillary teeth of the volunteer with Computed Tomography (CT) scanning technology, Saved the two-dimensional sectional image to Dicom data form from CT. Utilizes Mimics10.0,Pro Engineer and Marc2005 software to set up the three-dimensional finite elements analysis model.2 .Setting three planting angles(30°,60°,90°),the expert would load 200 g forces which is angled 0°,45°,90°separately with occlusal plane to different Micro-implants.Result:1. Three-dimensional finite element model of part of maxillary-micro-implant. with three implantation angle including 30°,60°and90°was successfully established. 2. The stress on the cortical bone were concentrated in cervix regional of Implanted micro-implant; Stress of cortical on the Implantation angle of 30°is maximum with others to different load angles. Its stress change significantly and witch stress decreasing rapidly. When the implantation angle is between 60°to 90°, the stresses have little change in any locate angle. 3. we got the maximum stresses on the cortical bone in these Implantation angles and force directions.4. When the implantation angle is 30°,the stresses concentrate in the area between micro-implant's cervix to its third thread. The stresses declines as the load angle increases, and get the minimum in the angle of 90°. When the implantation angle is between 60°to90°, the stresses change inevitably with different load angles. Finally, we got the maximum stresses on the implant in these Implantation angles and force directions.Conclusion:1.Appling advanced CT technology allied with three-dimensional finite element modeling and analysis software, we have established a fine similar in geometry and mechanics three-dimensional finite element model of the organization which contains a part of maxillary, a tooth and a micro-implant and can provide data for analysis.2. Only from the mechanical considerations, micro-implant implanted at any angle can endure 200g load power at different angle, which cannot cause bone tissue damage.3. We should plant implant at the angle between 60°~ 90°clinically,otherthan 30°. 4. Being planted at the angle of 90°, the micro-implant may penetrate mandibular cortical bone to the cortical bone surrounding with the root of tooth. So we should analysis the X-ray films or CT results before choosing 90°as the planting angle.