Objective To analyze the stress distribution of bone around the dental implants with lateral immediate loading of different angles by three dimensional finite element.Methods An adult edentulous mandible was adopted for CT scanning.The CT image was imported to universal surgical integration system to establish a mandible three dimensional mesh model.The real shape of standard thread implant was simulated and the finite element model of mandible with dental implants for immediate loading was established.The models were immediately loaded with 150 N through the angle of 0°, 10°, 20°, 30°.The ANSYS 10.0 was used to analyze the Von Mises stress on the bone around dental implants.Results The accurate finite element model of mandible with dental implants for immediate loading was successfully established.The three dimensional finite element analytical results showed: Under axial load,the Von Mises stress of bone contact surface concentrated on the cortical bone of the implant cervix.The strain distribution was even, and centralized at the cortical bone of the implant cervix, cancellous bone of implant bottom and thread contact area.Under different lateral angle load, the Von Mises stress of bone contact surface also concentrated on the cortical bone of the implant cervix, but the maximum value was 4 times of the vertical loading,the strain distributed unevenly, mainly concentrated on the cortical bone of the implant cervix.With the load angle increased, the stress and the strain value also increased.Conclusion When an axial force was immediately loaded,the stress value and the strain concentration value of bone interface around the dental implants are not apparently concentrated, the stress is distributed well.While a lateral force is loaded, the stress values and the strain concentration values of bone interface around the dental implants apparently increase and the strain are distributed unevenly.%目的 用三维有限元的方法分析牙种植体不同角度即刻负重的骨界面应力分布规律.方法 选成人无牙下颌骨进行薄层螺旋CT扫描,将扫描图像导入通用外科手术集成系统,建立下颌骨三维网格模型.模拟标准的螺纹实心种植体,建立种植体一下颌骨即刻负重的三维有限元模型.以150 N的力轴向加载和分别10.、20.、30.侧向加载,应用ANSYS 10.0分析软件分析种植体骨界面的Von Mises应力及应变.结果 成功地建立了一种即刻角度负重的种植体有限元模型;三维有限元分析结果示:轴向加载时骨界面的Von Mises应力集中于颈部骨皮质,应变分布均匀,以颈部骨皮质、底部骨松质及螺纹接触部位的松质骨较为集中;侧向不同角度加载时骨界而的Von Mises应力也集中于颈部骨皮质,但最大值是垂直加载时的4倍,应变分布不均匀,主要集中于颈部骨皮质;随着加载角度的增加,应力、应变值也增加.结论 即刻轴向负重时,种植体周围骨质应力及应变无明显集中,分布均匀,侧向负重时应力、应变明显增大,分布不均匀.
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