基台角度对种植体周围骨组织应力分布的影响

Influence of abutment angle on stress distribution of bone tissue around the implant

目的分析基台角度和咬合力大小的变化对种植体周围牙槽骨应力分布及大小的影响,为角度基台的合理应用提供理论依据。方法使用锥形束计算机扫描成像技术(cone beam computed tomography,CBCT)对即将种植患者下颌骨进行影像学扫描。使用Mimics、Geomagic Studio以及UGNX软件建立骨组织、种植体以及不同角度(15°,25°,35°)基台的实体结构模型。导入ABAQUS6.13有限元分析软件中建立有限元模型。分别在角度基台表面施加100 N和200 N咬合力,模拟分析改变基台角度时,种植体周围骨组织的应力变化。结果施加咬合力后,种植体颈部倾斜侧皮质出现不同程度的应力集中,应力集中区域随着基台角度的增大而增加,骨组织内应力均值与基台角度呈正相关。随着咬合力的增大,基台角度增大使得种植体倾斜侧皮质骨应力值增加,25°组增加趋势较缓,35°组较其余两组有明显增加。结论咬合力较大时,基台角度增加更容易造成种植体周围皮质骨应力集中,因此,在进行角度基台种植修复时,应关注患者的皮质骨厚度及评估患者种植区骨量,避免使用过大角度的基台,必要时应降低患者的咬合力以促进种植体形成骨结合。

Objective To evaluate the stress distribution of the bone around the implant with different angled abutments under different occlusal forces for providing a theoretical basis for reasonable application of the angled abutment in clinic.Methods The cone-beam computed tomography(CBCT)was used to collect the images of mandible of the patient to be implanted.The solid structures of the bone around the implant and the implants with different angled abutments(15°,25°,35°)were restricted with the software of Mimics,Geomagic Studio and UGNX.And the finite element(FE)model was established to research the stress variations in the bone under different occlusal forces(100,200 N)in ABAQUS6.13 software.Results After applying the occlusal force,the stress concentration in bone on the inclined side of the neck of the implant was different in each group,and it was increased with the increase of the angle of the abutment,and the mean stress in bone tissue was positively correlated with the angle of the abutment.The stress value of cortical bone on the inclined side was increased with the increase of the occlusal force and the angle of the abutment,and it was significantly increased in 35°group compared with the other two groups.Conclusion When applying the large occlusal force,the increase of the angle of abutment is prone to cause the stress concentration of cortical bone around the implant.Therefore,when performing angle abutment implant restoration,it is necessary to pay attention to the cortical bone thickness and evaluate the bone mass in planting area,and avoid using abutments with excessive angles.It is important that the occlusal force should be reduced to promote the osseointegration.