上颌后牙区、上颌窦、颧骨及颧骨种植体的三维有限元模型建立

目的:探讨上颌骨后牙区、上颌窦、颧骨及颧骨种植体的三维有限元建模方法。方法:采用螺旋CT扫描正常成人颅颌骨,利用3D-Doctor软件进行数据采集,数据导入ABAQUS软件中建立三维有限元模型,并模拟建立颧骨种植体模型。结果:建立的三维有限元模型几何相似性好,在操作平台上可随意观察。结论:采用CT扫描技术及ABAQUS建模技术可以建立切实可行的上颌骨后牙区、上颌窦、颧骨及颧骨种植体的生物力学模型。     

硬腭骨膜下种植体支持的赝复体修复无牙上颌骨缺损有限元模型的建立

目的：为种植赝复体设计,建立硬腭骨膜下种植体支持的赝复体修复无牙上颌骨缺损的三维有限元模型。方法：利用Mimics软件读取CT数据并初步构建颅上颌3D模型,经逆向工程软件Geomagic拟合模型生成非统一有理B样条曲面,Pro-E软件生成种植体,最终在Ansys中编辑装配完成并进行材料赋值和网格划分。结果：获得了由225、073个单元,76、682个节点组成的具有较高几何和生物相似性的H标三维有限元模型。结论：根据CT数据联合运用Mimics,Geomagic,Pro—E和Ansys软件,可以建立满意的复杂三维有限元模型。     

带凹槽螺纹种植体三维有限元模型的建立

目的：利用CAD软件的自适应功能建立包含Branemark TiUniteTM型带凹槽种植体骨块三维有限元模型。方法：应用pro/E软件根据种植体相关参数,建立牙种植体、冠修复体、松质骨和皮质骨三维实体模型,利用自适应功能生成装配体,导入Ansys Workbench10.0CAE软件中,进行单元划分建立有限元模型,应力加载后进行模型准确性的检测。结果：建立了包含真实螺纹种植体的下颌骨骨块三维有限元模型。结论：应用Pro/E软件自适应功能建立包含种植体的下颌骨骨块的三维有限元模型,为种植修复三维有限元分析提供了一种准确、灵活、快速的平台。     

双变量正畸微种植体骨块三维有限元模型的建立

目的：利用CAD/CAE软件的自适应和无缝参数传递功能,建立可自动改变直径和长度的微种植体下颌骨骨块三维有限元模型,为微种植体的生物力学分析、优化设计和选择提供快捷灵活的平台。方法：利用Pro/E软件,根据微种植体相关参数以及松质骨、皮质骨的几何外形,建立可以自适应改变的微种植体骨块实体模型,设定微种植体的直径（D）和长度（L）为变量,变化范围分别为D（0.5mm～1.0mm）,L（5.0mm～13.0mm）,导入Ansys workbench软件中,进行单元划分及模型准确性检测。结果：建立了可以自适应改变微种植体参数的下颌骨骨块三维有限元模型。结论：应用CAD/CAE软件的自适应和无缝参数传递功能,可以建立复杂的微种植体以及下颌骨骨块装配体的三维有限元模型。     

利用HAUSER投影仪建立螺纹种植体三维有限元模型

目的利用四种不同规格形状螺纹种植体，建立含种植体的下颌骨三维有限元模型。方法利用HAUSER投影仪获取种植体的建模数据，使用工程软件Pro／E2001建立三维实体模型并输入到ANSYS程序中成为ANSYS文件并行Boolern运算、网格化，分别形成含有四种种植体的下颌骨三维有限元模型。结果建立了含有四种不同规格形状螺纹结构种植体的下颌骨三维有限元模型，单元和节点分别是，A型种植体：324549，81202；B型种植体：544089，88550；C型种植体：1130845，20375；D型种植体：569123，105759。结论采用投影记录、利用相关软件建立的含不同形状的种植体下颌骨模型具有良好的几何相似性与物理相似性。     

个性化下颌体部钛植入支架三维有限元模型的建立

目的：建立个性化下颌体部钛植入支架三维有限元模型,为进一步的生物力学设计奠定基础。方法：利用正常人下颌骨三维有限元模型,模拟一侧体部缺损,对下颌钛植入支架的曲面进行拟和,并对钛植入支架上缘预留孔道进行生成和定位。结果：建立了个性化下颌体部钛植入支架三维有限元模型。结论：获得了．与模拟真实下颌骨体部缺损相匹配钛植入支架的三维有限元模型,为结构设计打下基础。     

微型种植体下颌骨三维有限元模型的建立

目的探索一种可行的建立包含微型种植体不同植入方向及角度的下颌骨三维有限元模型的方法,为支抗种植体相关研究提供模型支持。方法本文基于CT数据,采用CAD（Pro/E）及ANSYS软件,用轮廓延伸法建立简化下颌骨模型,模拟临床实际常用植入部位,建立微型种植体不同植入方向及角度的下颌骨三维有限元模型。结果建立了5个真实螺纹形态的微型种植体植入的下颌骨有限元模型。结论本实验建立的有限元模型的几何相似性、生物力学相似性及临床适应性均达到实验要求,为支抗种植体三维有限元分析提供了一种准确、灵活、快速的平台。     

圆柱状二段式钛涂层表层多孔种植体的制作

目的 报告一种表导多孔种植体制作方法,并对此种种植体进行表层测定。方法 选用等离子喷涂方法,将纯钛粉喷涂到纯钛桩表面,形成表面多孔种植体,并对涂层成份进行分析,力学测试粘接强度及扫描电镜观察表面形态。结果 种植体表面呈５０～４００ｕｍ粗糙多孔状,表面成份为氧化钛、氮化钛及钛,与基桩结合牢固。结论 用此方法制成的表层多孔种植体符合理想种植体标准,为临床上表面多孔种植体系统提供了制作方法。     

钛种植体表面磷酸化与仿生矿化的实验研究

目的 探讨钛表面磷酸化处理的方法,并观察磷酸化钛表面在模拟体液内进行仿生矿化的实验效果,以期为钛种植体表面改性提供新的研究思路.方法 用磷酸对钛表面进行酸蚀处理,再以此为仿生模板进行体外仿生矿化研究.结果 钛磷酸化处理后形成粗糙、多孔的表面,再经高温高压处理,生成与钛表面化学键合的Ti( H2PO4)3晶体层,此层富含- OH及- PO43-离子,具备生物矿化诱导功能,从而活化钛种植体表面.结论 磷酸酸蚀可以实现对钛种植体表面的磷酸化改性.     

钛种植体表面微弧氧化处理后的生物力学及组织形态学研究

目的对表面微弧氧化(MicroarcOxidation ,MAO)处理后的纯钛种植体进行动物种植实验研究,评估改进的MAO工艺应用于钛种植体的实际效果。方法建立犬下颌缺牙模型,设计纯钛材料种植体,分别经两种MAO处理(MAO - 1和MAO - 2 )后,植入犬下颌骨,采用拉出测力实验、扫描电镜观察、种植体-骨界面X射线能谱扫描的研究方法,对植入3、6、12周种植体的生物力学稳定性及界面特点进行评价,以未经处理纯钛种植体作为对照,实验数据以SPSS软件进行统计分析。结果各组种植体的骨结合力随时间逐渐升高,在所测试的3个时间点内,各组间的骨结合力都有明显统计学差异,MAO - 1组>MAO - 2组>纯钛对照组;X射线扫描结果表明,MAO处理后的种植体-骨界面附近钙磷含量较高,提示新生骨基质钙化良好。结论MAO处理工艺可以提高种植体表面氧化层的生物活性,纯钛种植体经改进的MAO处理后的可以进一步缩短骨结合时间,提高骨结合力。     

加工医用纯钛植入体所用切削液的研究

目的：提高医用纯钛植入绵加工质量，研究采用了一种专用切削作医用纯钛加工。方法：参考美国专利自行配制一一种切削液，通过表面形貌和残余应力分析比较干切组（Ａ）、蒸馏水组（Ｂ）、与切削液组（Ｃ）的切削效果。结果：该切削液不含有害物质，能较好地减小残余应力，提高切削质量。结论：该切削液是一种有效的切削保护对加工提高，延长钛工件的疲劳寿命有很大帮助。     

A novel root analogue dental implant using CT scan and CAD/CAM: selective laser melting technology

Direct laser metal forming (DLMF) is a new technique which allows solids with complex geometry to be produced by annealing metal powder microparticles in a focused laser beam, according to a computer-generated three-dimensional (3D) model. For dental implants, the fabrication process involves the laser-induced fusion of titanium microparticles, in order to build, layer by layer, the desired object. Modern computed tomography (CT) acquisition and 3D image conversion, combined with the DLMF process, allows the fabrication of custom-made, root-analogue implants (RAI), perfect copies of the radicular units that need replacing. This report demonstrates the successful clinical use of a custom-made, root-analogue DLMF implant. CT images of the residual non-restorable root of a right maxillary premolar were acquired and modified with specific software into a 3D model. From this model, a custom-made, root-analogue, DLMF implant was fabricated. Immediately after tooth extraction, the root-analogue implant was placed in the extraction socket and restored with a single crown. At the 1-year follow-up examination, the custom-made implant showed almost perfect functional and aesthetic integration. The possibility of fabricating custom-made, root-analogue DLMF implants opens new interesting perspectives for immediate placement of dental implants.     

不同表面处理方法对CAD/CAM氧化锆种植体表面显微形貌的影响研究

目的：：研究采用不同表面处理方法对CAD/CAM氧化锆种植体表面显微形貌特征及粗糙度的影响。方法：通过CAD/CAM技术加工氧化锆圆盘与一段式氧化锆种植体( Y-TZP, WIELAND),根据表面处理方式分为终烧结表面、喷砂表面及喷砂加热酸蚀处理表面;标准对照组选用BEGO钛种植体表面。各组圆盘试件及种植体用扫描电子显微镜及Keyence 3D激光显微形貌测量显微镜进行表面显微形貌观察与测量。采用单因素方差分析比较各组统计学差异。结果：各组CAD/CAM氧化锆试件表面显微形貌观察显示,喷砂后表面出现边缘锐利的凹坑及沟槽;喷砂加热酸蚀处理后,氧化锆表面可见纳米级的微小孔隙及沟纹。氧化锆种植体粗糙度测量结果显示：终烧结组的表面粗糙度值(Ra=0.69μm)显著低于其他3组(P<0.001),喷砂组Ra值(Ra=1.30μm)显著低于喷砂加热酸蚀组(Ra=1.49μm)及BEGO钛种植体组(Ra=1.57μm)(P<0.01),而喷砂加热酸蚀组与BEGO钛种植体组则无显著差异(P=0.196)。结论：CAD/CAM氧化锆试件终烧结后喷砂或喷砂加热酸蚀处理均可获得较为理想的表面粗糙度,热酸蚀处理能够改变氧化锆表面的纳米级微观结构。     

不同粗糙表面的纯钛种植体表面的体外细胞培养评价

目的：本文通过对不同粗糙度表面纯钛种植体（光滑、机械表面、大粗糙表面、2种不同的微粗糙表面）的体外细胞培养评价,寻找具有较好的细胞附着的表面状态。方法：对5种不同粗糙度的钛种植体表面进行2BS成纤维细胞培养,通过光镜和电子显微镜对材料表面的成纤维细胞的数量和形态、细胞的粘附状态和细胞与种植体的关系进行了观察和分析。结果：粗糙表面的钛种植体对成纤维细胞的＂诱导能力＂更强,表现为细胞迁徙、附着于二者的细胞数目比光滑表面的钛板为多,细胞桥形成更早。结论：钛种植体表面微粗糙化提高钛材的生物相容性。     

种植磁性覆盖义齿的三维有限元模型的建立

目的 建立磁性附着体固位的种植覆盖义齿的三维有限元模型,为分析磁性附着体对种植覆盖义齿的应力分布的影响奠定基础。方法 采取DICOM 建模法建模,基于CT 医学图像,利用Mimics 医学影像三维重建软件、Geomagic studio 逆行工程软件和SolidWorks 三维设计仿真软件来建立三维有限元实体模型。结果 建立了下颌双种植体支持的种植磁性覆盖义齿的三维有限元模型。结论 该模型可用于分析磁性附着体对种植覆盖义齿应力分布的影响。     

Osseointegration and foreign body reaction: Titanium implants activate the immune system and suppress bone resorption during the first 4 weeks after implantation

Background

Osseointegration mechanisms are still not entirely understood.

Purpose

The present pilot study aims at demonstrating the involvement of the immune system in the process of osseointegration around titanium implants, comparing bone healing in the presence and absence of a titanium implant.

Materials and Methods

Fifteen New Zealand White rabbits had one osteotomy performed at each of the distal femurs; on one side, no implant was placed (sham) and on the other side a titanium implant was introduced. Subjects were sacrificed at 10 and 28 days for gene expression analysis (three subjects each time point) and for decalcified qualitative histology (six subjects each time point). At 10 days, the three subjects for gene expression analysis were part of the six subjects for histology.

Results

Gene expression analysis: at 10 days, ARG1 was significantly up‐regulated around titanium, indicating an activation of M2‐macrophages. At 28 days CD11b, ARG1, NCF‐1, and C5aR1 were significantly up‐regulated, indicating activation of the innate immune system, respectively M1‐macrophages, M2‐macrophages and group 2‐innate lymphoid cells, neutrophils, and the complement system; on the other hand, the bone resorption markers RANKL, OPG, cathepsin K, and TRAP were significantly down‐regulated around titanium. Histology: at 10 days new bone formation is seen around both sham and titanium sites, separating bone marrow from the osteotomy/implant site; at 28 days no bone trabeculae is seen on the sham site, which is healing at the original cortical level, whereas around titanium implants, bone continues into organization of more mature cortical‐like bone, forming a layer between the implant and the bone marrow.

Conclusions

The presence of a titanium implant during bone healing activates the immune system and displays type 2 inflammation, which is likely to guide the host‐biomaterial relationship. At the same time, bone resorption is suppressed around titanium sites compared to sham sites after 4 weeks of implantation, suggesting a shift to a more pronounced bone forming environment. This suggests two important steps in osseointegration: identification of the titanium foreign body by the immune system and the development of a bone forming environment, that at tissue level translates into bone build‐up on the titanium surface and can be perceived as an attempt to isolate the foreign body from the bone marrow space.     

上颌骨功能性重建中用钛植入体重建颧上颌支柱的生物力学研究

目的:对腓骨+不同钛植人体的上颌骨重建的三维有限元模型进行生物力学分析,研究上颌骨功能性重建中用钛植入体重建颧上颌支柱的可行性.方法:分别对腓骨+重建钛板、腓骨+钛网和腓骨+颧种植体3种上颌骨重建的三维有限元模型,于双侧后牙区垂直加载,研究钛植入体的应力和位移分布.结果:腓骨+重建钛板和腓骨+钛网这2种类型在钛板和钛网...     

Finite element analysis to determine implant preload

STATEMENT OF PROBLEM: The nature of the forces used to clamp implant components together, and how they are generated and sustained, is lacking in the literature. PURPOSE: This study examined the dynamic nature of developing the preload in an implant complex using finite element analysis. METHODS: The implant complex was modeled in accordance with the geometric designs for the Nobel Biocare implant systems. A thread helix design for the abutment screw and implant screw bore was modeled to create the geometric design for these units of the implant systems. Using the software programs HyperWorks and LS3D-Dyna, 2 3-dimensional finite element models of (1) a Branemark System 3.75 x 10-mm titanium Mark III implant, a CeraOne titanium abutment, a Unigrip gold alloy abutment screw, and (2) a Replace Select System 4.30 x 10-mm titanium implant, a Straight Esthetic titanium abutment, and a TorqTite titanium abutment screw were created. Modeling the threads to the machining specifications permitted simulation of screw tightening. The abutment screws were subjected to a tightening torque in increments of 1 Ncm from 0 to 64 Ncm using ABAQUS software. Using these models, the effect of the coefficient of friction on the development of preload amount in the implant complex during and after abutment screw tightening was determined. In the first experiment, the coefficient of friction was set to 0.20 between the titanium bearing surface of the abutments and the implant bearing surfaces, and 0.26 between the gold abutment screw and the titanium implant screw bore. In the second experiment, the coefficient of friction was varied; the titanium implant and titanium abutment bearing surfaces were set to a coefficient of friction of 0.20, whereas the Mark III gold and the Replace Select titanium abutment screws and their respective titanium screw bores in the implants were set to 0.12. The preload amount (N) was determined from the finite element analysis. RESULTS: The stress distribution pattern clearly demonstrated a transfer of preload force from the screw to the implant during tightening. A preload of 75% of the yield strength of the abutment screw was not established using the recommended tightening torques. CONCLUSION: Using finite element analysis, a torque of 32 Ncm applied to the abutment screws in the implant assemblies studied in the presence of a coefficient of friction of 0.26 resulted in a lower than optimum preload for the abutment screws. To reach the desired preload of 75% of the yield strength, using a torque of 32 Ncm applied to the abutment screws in the implant assemblies studied, the coefficient of friction between the implant components should be 0.12.     

包含TM种植体的颌骨有限元模型研究

目的研究快速准确建立包含TM（tension more）种植体颌骨三维有限元模型的方法,为种植修复的生物力学分析打下基础。方法通过逆向工程技术,将二维下颌骨CT图片应用Mimics软件转化为三维实体模型,并建立包含TM种植体的真实下颌骨B/2类骨质（皮质骨和松质骨含量相当）的有限元模型。结果快速准确地建立了包含TM种植体的颌骨有限元模型。结论 CT技术、医学数字图像通信标准（digital imaging and communi-cations in medicine,DICOM）的应用使有限元模型的建立更为精确,Mimics软件直接建立三维模型后通过逆向工程技术,直接导入Geo magic Studio 9.0软件提高了建模的效率。     

不同加工工艺对纯钛支架力学性能的影响

目的 探讨不同加工工艺对纯钛支架力学性能的影响。方法 分别用数控铣削、3D打印和传统铸造工艺制作纯钛试件后用X线探伤仪进行检测。试件进行一般打磨抛光和精细打磨抛光后分别测量试件表面粗糙度;用扫描电子显微镜(SEM)分别对各组试件进行表面观察;用万能试验机测量每组试件抗弯曲强度和剪切强度。结果 X线探伤仪显示部分铸造制作的试件内部含有气孔。一般打磨抛光后数控铣削表面粗糙度最小,3D打印粗糙度最大;精细打磨抛光后数控铣削表面粗糙度变化最小;扫描电镜显示数控铣削制作的试件表面致密纹路清晰。万能试验机测量强度显示:数控铣削制作的试件其抗弯曲强度与剪切强度均为最大。结论 数控铣削加工后的纯钛试件结构最为致密,表面粗糙度最小,力学强度最大。