微型种植体单一载荷与复合载荷的生物力学效应及规律

发布时间：2018-05-17 01:29

  本文选题：微种植体 + 单一载荷　； 参考：《河北医科大学》2015年硕士论文

【摘要】：目的：临床正畸治疗过程中,支抗的控制常常是影响治疗效果的关键因素,若支抗控制不好甚至可以导致治疗的失败。随着原有的支抗控制装置已不能满足临床需要,近年来微型种植体支抗技术逐渐应用于临床正畸治疗,并且由于其尺寸小、植入位置灵活、手术创伤小等原因受到广泛欢迎,极大地拓展了正畸治疗的范围。但微型种植体脱落情况时有发生,据报道成功率89%,影响了支抗种植体在临床更为广泛的开展。影响种植体稳定性的因素包括生物学稳定性和生物力学稳定性。材料学的发展极大地提高了种植体的生物学稳定性,因此种植体的生物力学稳定性逐渐受到重视。学者们对修复种植体的力学影响做了大量研究,但微型种植体明显不同于修复种植体,种植体植入位置及对其载荷的方式都有很大的差别。一些学者对微型种植体植入角度及载荷方向做了研究,发现二者均明显影响了种植体-骨界面的应力分布。但在临床实际操作中,对支抗种植体的载荷方式更加复杂多变,可能为单一载荷,也可能为复合载荷,并且会根据不同的正畸治疗目的而改变载荷方向。目前,有关不同载荷方式对种植体-骨界面应力分布的作用效果和规律尚不明确,未见有文献报道。三维有限元法是分析口腔种植体生物力学的重要方法和手段,已广泛应用于口腔领域。此方法通过建立精确的牙颌系统模型,可真实的模拟不同载荷下种植体及其周围组织的位移及应力的变化,由于受其他因素影响较小,是目前研究微种植体比较可靠的一种方法。本实验通过三维有限元分析法,建立了两种角度植入微种植体的骨块模型,模拟临床不同植入角度时对种植体施加单一或复合载荷,并观察不同载荷方式下种植体周围组织的应力分布和位移变化,探讨种植体不同植入角度、不同载荷方式种植体-骨界面应力分布的规律,为临床应用提供理论依据,以期提高微种植体的稳定性。方法：1实验设备计算机：笔记本工作站,Dell precision (Intel(R) Core(TM) i7-4800MQ CPU@2.70GHz:32G内存,win7,64位操作系统)软件包：Mimics, Catia V5,Hyperworks 12.0, Abaqus6.13, excel,截图工具2微种植体—颌骨模型2.1建立模型临床为了使作为支抗的微种植体可以植入颌骨的任意部位,其直径和长度的范围是受到限制的。本文模拟了一个直径为1.6mm的微种植体,螺纹高度0.3mm、螺纹间距0.5mm、螺纹顶角600,材料为纯钛。而种植体长度一般由植入部位的解剖形态决定,本文建立的骨块模型为长20mm、宽20mm.、高10mm(表面为皮质骨,内部为松质骨,其中皮质骨厚度1mm,其余为松质骨)的立方体,以使其有足够的宽度来评估微种植体周围的应力分布。因此设定微种植体骨内长度为8mm。2.2装配微型种植体-下颌骨实体模型以骨块模型表面几何中心为种植体植入点,设定通过植入点平行于一侧骨边缘为X轴,平行于另一侧为Y轴,垂直于骨表面为Z轴。种植体植入方向分别为：垂直植入和将种植体向Y轴正向倾斜45度角植入。2.3载荷力大小、方式及方向微种植体可承受的正畸力值通常不超过3N。根据力学规律计算,设定Load-C加载力值为2×√2N,其余均为2N。载荷方式为单一载荷或双载荷同时进行。所有加载方向平行于X-Y平面。载荷点位于种植体的颈部。2.4实验分组设定与X轴正向方向一致时加载方向为0°。实验分组如下：第一组：微种植体垂直于x-y平面植入Loadl-A施加与x轴正向成0°的正畸力2NLoadl-AB同时施加与x轴正向成0°和180°两个方向的正畸力各2NLoadl-C施加与x轴正向成90°的正畸力2×√2 NLoadl-DE同时施加与x轴正向成45°和1350两个方向的正畸力各2NLoadl-FG同时施加与x轴正向成250和1550两个方向的正畸力各2N第二组：微种植体与y轴正向成45°植入LoadⅡ-A施加与x轴正向成0°的正畸力2NLoadⅡ-AB同时施加与x轴正向成0°和180°两个方向的正畸力各2NLoadⅡ-C1施加与x轴正向成90°并与y轴正向成0°的正畸力2NLoadⅡ-C2施加与x轴正向成90°并与y轴正向成0°的正畸力2×√2NLoadⅡ-D施加与x轴正向成450的正畸力2NLoadⅡ-DE同时施加与x轴正向成450和135°两个方向的正畸力各2NLoadⅡ-F施加与x轴正向成25°的正畸力2NLoadⅡ-FG同时施加与x轴正向成250和1550两个方向的正畸力各2NLoadⅡ-H施加与种植体长轴方向成0°的正畸力2N3材料3.1实体建模利用电子计算机技术,建立颌骨和种植体的三维模型,形成垂直装配和倾斜45度装配。假设模型中的各种材料和组织为连续、均质、各向同性的线弹性材料,材料变形为弹性小变形。3.2网格划分利用电子计算机技术,导入三维模型到有限元建模软件Hyperwork12.0的Hypermesh模块中,完成整个模型网格划分。3.3部件连接将有限元网格模型导入到Abaqus6.13中,根据提供的不同部件的材料属性,建立并赋予各部件材料属性。设定种植体—骨界面间摩擦系数为0.3。4计算利用Hyperworks13.0的Hyperview模块查看计算结果,采集各组Von-Mises应力值、压应力值、拉应力值及位移值,并分析其应力分布和应变规律。结果：1建立了微种植体垂直和倾斜45度植入的颌骨模型,其生物相似性好,满足力学运算要求。2在微种植体以垂直和倾斜植入的两组模型中,不同加力方式下的应力和位移峰值主要集中在有力值加载部位的骨边缘处。这说明应力和位移的峰值主要集中在皮质骨。由皮质骨过渡到松质骨,应力和位移的数值呈现递减趋势。3当微种植体垂直植入时,Von-Mises应力峰值由8.72到0.7186MPa,位移峰值由5.525到0.2016μm。其中相交成90°的复合载荷组LoadⅠ-DE,应力峰值及位移峰值最大；其次为单一载荷组LoadⅠ-A即传统加力方式,然后是相交成130°的复合载荷组LoadⅠ-FG,峰值最小的是方向相反的复合载荷组LoadⅠ-AB。值得注意的是,加载方向为90°,加载力值为2×√2 N的载荷组LoadⅠ-C与相交成90°的复合载荷组LoadⅠ-DE应力峰值与位移峰值相差不多。4倾斜植入时,Von-Mises应力峰值由7.293到0.2612MPa,位移峰值由5.237到0.1597μm。最大值依然出现在LoadⅡ-DE组,最小值也同样为LoadⅡ-AB组。单一载荷时施加相同正畸力(2N)的LoadⅡ-A、LoadⅡ-F、 LoadⅡ-D、LoadⅡ-C1、LoadⅡ-H在应力和位移峰值上呈现出递减的趋势；施加2×√2N的LoadⅡ-C2与施加2N的LoadⅡ-A应力和位移峰值相差不多。5各载荷方式下,倾斜植入组应力峰值均小于垂直植入组；而Load-FG组倾斜植入时的位移峰值与垂直植入时差别不大。结论：1种植体垂直植入及倾斜植入,同时加载两个方向相反、大小相等的垂直于种植体长轴的力时,骨界面应力分布最均匀,也最有利于种植体的稳定。2种植体垂直植入,复合载荷时的合力基本符合平行四边形法则,复合载荷交角越小合力越大,骨界面应力峰值越大,载荷方向越接近于相反,骨界面受力越小。3种植体倾斜植入,所有单一载荷及复合载荷的骨界面应力分布均优于种植体垂直植入；复合载荷时的合力不符合平行四边形法则；载荷力矩随着载荷方向的不同发生改变,载荷力矩越小,种植体-骨界面所受应力越小,具有重要的临床指导意义。
[Abstract]:Objective: in the course of clinical orthodontic treatment, the control of anchorage is often the key factor affecting the effect of the treatment. If the control of the support is not good or even can lead to the failure of the treatment, the microimplant anchorage technique has been gradually applied to clinical orthodontic treatment in recent years with the original anchorage control device. Small, flexible implantation, small trauma and other reasons are widely welcomed, which greatly expand the scope of orthodontic treatment. However, the occurrence of the miniature implants occurs when the success rate is reported to be 89%, which affects the extensive development of the anchorage implant. The factors affecting the stability of the implant include biological stability and biological force. The development of material science has greatly improved the biological stability of the implant, so the biomechanical stability of the implant has been gradually paid attention to. Scholars have done a lot of research on the mechanical effects of repairing implants, but the microimplants are obviously different from the implant, the implant placement and the way they load the implant. A lot of differences. Some scholars have studied the angle of implants implantation and the direction of load. It is found that the stress distribution of the implant bone interface is obviously affected by the two. But in clinical practice, the load mode of the anchorage implant is more complex and changeable, it may be a single load, and it may be a compound load, and it will be based on different loads. At present, the effects and laws of different load modes on the stress distribution of implant bone interface are not yet clear, and no literature has been reported. Three dimensional finite element method is an important method and means to analyze the biomechanics of oral implant. It has been widely used in the field of oral cavity. The accurate model of dental maxillary system can simulate the change of displacement and stress of the implant and its surrounding tissue under different loads. Because of the small influence of other factors, it is a more reliable method to study the microimplants. This experiment has established two kinds of bone mass model of implants by three-dimensional finite element analysis. To simulate the stress distribution and displacement changes of the tissue around the implant under different load modes, the stress distribution and displacement of the implant bone interface in different loading modes are observed and the stress distribution of implant bone interface in different loading ways is investigated. Method: 1 experimental equipment computer: notebook workstation, Dell precision (Intel (R) Core (TM) i7-4800MQ CPU@2.70GHz:32G memory, win7,64 bit operating system) software package: Mimics, Catia V5, 12, 2 micro implant jaw model 2.1 to establish model clinical for the purpose of making A micro implant as an anchorage can be implanted in any part of the jaw. Its diameter and length are limited. A micro implant with a diameter of 1.6mm is simulated in this paper. The height of the thread is 0.3mm, the thread spacing is 0.5mm, the thread top angle is 600, the material is pure titanium. The length of the implant is generally determined by the anatomical shape of the implant. This article is established in this article. The bone mass model is long 20mm, wide 20mm., high 10mm (the surface is cortical bone, the internal is the cancellous bone, the cortical bone thickness 1mm, the rest is the cancellous bone) cube, so that it has enough width to evaluate the stress distribution around the microimplant. Therefore, the microimplant bone length is 8mm.2.2 assembly Micro Implant mandible solid model. Using the surface geometry center of the bone block model as the implant insertion point, the implant point is parallel to one side of the bone edge as the X axis, parallel to the other side and the Y axis and the Z axis on the bone surface. The implant direction is the vertical implantation and the implantation of the implant to the Y axis in the direction of the.2.3 load of 45 degrees, and the direction and direction of the implant. The orthodontic force values of the body are usually not more than 3N. according to the mechanical law, and the Load-C loading force is set at 2 x 2N, the rest are both single load or double load with 2N. load. All loading directions are parallel to the X-Y plane. The load point is located at the neck of the implant and the X axis is in the same direction as the positive direction of the X axis. The experimental group was 0 degrees. The first group was as follows: the first group: the micro implant was implanted vertically on the X-Y plane by Loadl-A to apply orthodontic force 2NLoadl-AB with the positive force of the X axis and the orthodontic force of the X axis forward into 0 degrees and 180 degrees. The orthodontic force 2 * 2 NLoadl-DE of the X axis was applied to the positive force of the X axis and the positive force of the X axis was simultaneously applied to the X axis forward 45 degrees. The orthodontic forces in the 1350 and two directions were simultaneously applied to the orthodontic forces of the X axis and the forward formation of the orthodontic forces in 250 and 1550 two directions: the micro implants and the Y axis forward 45 degree implantation to Load II -A exerted the orthodontic force 2NLoad II -AB at the positive force of the X axis and the forward formation of the X axis and the orthodontic force of the X axis forward 0 and 180 degrees two. The orthodontic force exerted by the orthodontic force 2NLoad II -C2 with the positive force of the X axis 90 degrees and the positive 0 degrees of the Y axis is applied to the orthodontic force of the X axis forward 90 degrees and the positive force of the Y axis, 2 * 2NLoad II -D exerted on the positive force of the X axis forward 450, and exerts the orthodontic force of the forward formation of the X axis and the forward formation of the 450 and 135 degrees in the forward 450 and 135 degree two directions. The orthodontic force 2NLoad II -FG is applied to the orthodontic force of the orthodontic force each of the X axis in 250 and 1550 directions and the orthodontic force 2N3 material is applied to the long axis of the implants and the orthodontic force 2N3 material 3.1 solid modeling using the electronic computer technology to establish the three-dimensional model of the jaw and the implant, forming the vertical assembly and the inclined 45 degrees assembly. All kinds of materials and tissues are continuous, homogeneous, isotropic linear elastic materials, the material is deformed into elastic small deformation.3.2 mesh division using electronic computer technology, the 3D model is introduced into the Hypermesh module of the finite element modeling software Hyperwork12.0, and the whole model grid is divided into the.3.3 component connection and the finite element mesh model is introduced into the model. In Abaqus6.13, according to the material properties of the different components provided, the material properties of each component are established and given. The friction coefficient between the implant bone interface is set up and the calculation results are examined by the Hyperview module of Hyperworks13.0, and the Von-Mises stress values, the compressive stress values, the tensile stress values and the displacement values are collected, and the stress points are analyzed. Results: 1 the mandible model of vertical and 45 degree implantation of micro implant was established. The biological similarity was good, and the stress and displacement peak in different loading modes were mainly concentrated in the bone edge of the loading position in the two models of the mechanical operation requirements that.2 was implanted vertically and tilted in the micro implant. The peak stress and displacement are mainly concentrated in the cortical bone. Transition from cortical bone to cancellous bone, the values of stress and displacement show decreasing trend.3, when the microimplant is vertically implanted, the peak value of Von-Mises stress is from 8.72 to 0.7186MPa, and the peak value of displacement is from 5.525 to 0.2016 mu m. in the compound load group of Load I -DE, the peak stress and the stress peak. The peak displacement is the largest, followed by a single load group Load I -A, that is, the traditional loading method, and then the composite load group Load I -FG intersected into 130 degrees, and the minimum peak is the Load I -AB. with the opposite direction of the load, which is worth noting that the loading direction is 90 degrees, the loading force value is 2 * 2 N and the compound load of Load I -C and intersecting 90 degrees. When the peak value of Load I -DE is not much different from the peak displacement peak, the peak value of Von-Mises stress is from 7.293 to 0.2612MPa, and the peak value of the displacement from 5.237 to 0.1597 mu m. still appears in the Load II -DE group, and the minimum value is also the Load II -AB group. II -C1, Load II -H showed a decreasing trend at the peak stress and displacement peak, and the difference between the Load II -C2 and the Load II -A stress and displacement peak of 2 x 2N was not much higher than that of the vertical implantation group, while the peak value of the tilted implant group was less than that of the vertical implantation group, while the peak displacement of the Load-FG group was not different from the vertical implantation time. Conclusion: 1 the vertical implantation of the implant and the inclined implants, while loading two opposite directions, and the same size perpendicular to the force of the long axis of the implant, the stress distribution of the bone interface is the most uniform and is most beneficial to the vertical implantation of the stable.2 implant of the implant. The resultant force of the compound load is basically in accordance with the parallelogram rule, the more the composite load is the intersection angle. The greater the small resultant force, the greater the stress peak of the bone interface, the closer the load direction to the opposite, the smaller the stress of the bone interface, the less the.3 implant is inclined, and the stress distribution of all the single load and the composite load is better than the vertical implantation of the implant; the resultant force does not conform to the horizontal quadrangle rule, and the load torque is along with the load direction. The smaller the load moment, the smaller the stress on implant bone interface.
【学位授予单位】：河北医科大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R783.6
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本文编号：1899311