圆柱种植体直径和长度的双因素分析

目的应用Ansys DesignXplorer模块,进行圆柱形种植体直径和长度的双目标稳健分析,为临床选择和设计种植体提供理论依据。方法建立包含圆柱状种植体的颌骨骨块三维有限元模型,设定种植体的直径（D）为2.5～5.0 mm,种植体长度（L）为6.0～16.0 mm,观察D和L变化对颌骨Von Mises应力峰值的影响,同时进行颌骨VonMises应力峰值对变量的敏感度分析。结果在一个变量取中间值时,垂直向加载情况下,随着D的增加,皮、松质骨的EQV应力峰值分别降低了44.66%和51.45%,随着L的增加,皮、松质骨的EQV应力峰值分别降低45.97%和52.15%;颊舌向加载情况下,随着D的增加,皮、松质骨的EQV应力峰值分别降低71.32%和58.50%,随着L的增加,皮、松质骨的EQV应力峰值分别降低21.66%和37.75%。在两种加载情况下,当D>3.7 mm且L>10.0 mm时,颌骨的EQV应力峰值对D和L的响应曲线曲率位于- 1和0之间;变量D比L对颌骨的EQV应力峰值的影响更明显。结论种植体直径的增大有利于改善颊舌向力的力学分布,长度的增大有利于改善垂直向力的力学分布;临床选择种植体时,只要骨量允许,种植体直径应不小于3.7 mm,长度应不小于10.0 mm;相对于长度而言,应更重视圆柱形种植体直径的选择和设计,而改善颌骨的宽度比改善颌骨的高度在缓和颌骨的应力分布中可能更有意义。     

种植体直径和长度在Ⅰ类骨质中的优化选择

目的:应用Ansys DesignXplorer模块,研究圆柱形种植体直径和长度同时连续变化对Ⅰ类骨质的颌骨应力影响,为临床选择和设计种植体提供理论依据。方法:建立包含圆柱状种植体的下颌骨Ⅰ类骨质骨块的三维有限元模型,设定种植体直径(D)变化范围为3.0~5.0mm,种植体长度(L)变化范围为6.0~16.0mm,观察D和L变化对颌骨Von Mises应力峰值的影响。同时进行颌骨Von Mises应力峰值对变量的敏感度分析。结果:随着D和L的增加,垂直向加载时,皮、松质骨的EQV应力峰值分别降低了54.5%和70.2%,颊舌向加载时,皮、松质骨的EQV应力峰值分别降低了73.5%和75.1%;当D大于3.8mm同时L大于9.0mm时,应力峰值的响应曲线的切斜率位于-1和0之间;在垂直向加载和颊舌向加载时,变量D比L更易影响皮质骨的EQV应力峰值。结论:种植体的直径比长度更易影响皮质骨的应力大小。从生物力学角度而言,对于Ⅰ类骨质,在临床上选择种植体时,种植体的直径应不小于3.8mm,种植体的长度应不小于9.0mm。     

I类骨质中正畸微种植体支抗直径和长度的优化设计

目的：探讨正畸微种植体支抗长度和直径对I类骨质下颌骨的应力和微种植体稳定性的影响,为临床设计I类骨质中微种植体支抗的最佳长度和直径提供理论依据。方法：建立包含正畸微种植体支抗的颌骨骨块的三维有限元模型,设定微种植体的直径和长度为变量,直径变化范围1.0～1.8mm,长度变化范围5.0～11.0mm。设定颌骨平均主应力峰值和正畸微种植体支抗位移峰值为目标函数。观察设计变量变化对目标函数的影响。结果：随着直径的增加,皮质骨、松质骨应力峰值和种植体位移分别降低了67.98%,64.06%,78.55%;随着长度变化皮质骨、松质骨的应力峰值和种植体位移分别降低了13.94%,61.32%,0.01%。结论：种植体支抗的直径对I类骨质颌骨的应力和种植体支抗稳定性的影响更显著。长度对I类骨质颌骨的应力和种植体支抗稳定性的影响并不显著。从生物力学角度而言,直径大于1.4mm种植体支抗更加适用于I类骨质的颌骨。     

种植体直径和长度在Ⅳ类骨质中的优化选择

目的:应用Ansys DesignXplorer模块,进行圆柱形种植体直径和长度同时连续变化时对Ⅳ类骨质的颌骨应力影响的分析。方法:建立了包含圆柱状种植体的下颌骨Ⅳ类骨质的骨块三维有限元模型,设定种植体直径(D)变化范围为3.0～5.0mm,种植体长度(L)变化范围为6.0～16.0mm,观察D和L变化对颌骨Von Mises应力峰值的影响。同时进行颌骨Von Mises应力峰值对变量的敏感度分析。结果:随着D和L的增加,垂直向加载时,皮质骨、松质骨的EQV应力峰值分别降低了63.9%和87.9%,颊舌向加载时,皮质骨、松质骨的EQV应力峰值分别降低了76.2%和92.7%;当D>4.0mmL>11.0mm时,应力峰值的响应曲线的切斜率位于-1～0之间;在垂直向加载和颊舌向加载时,变量L和D分别对皮质骨的EQV应力峰值的影响更明显。结论:颊舌向力的力学分布更易受种植体参数影响;松质骨的应力更易受种植体参数影响;种植体直径增加更有利于改善颌骨颊舌向加载下的应力分布,种植体长度的增加更有利于改善皮质骨垂直加载下的应力分布。从生物力学角度而言,对于Ⅳ类骨质在临床上选择种植体时,种植体的直径应≥4.0mm,种植体的长度应≥11.0mm。     

不同力作用下微种植体长度和直径的双变量优化分析

目的 探讨在不同力作用下,长度和直径同时连续变化情况下微种植体尺寸的优化设计,以期为临床上合理选择微种植体尺寸提供理论基础。方法 建立长度和直径连续变化的微种植体及周围颌骨组织的三维有限元模型,设定长度变化范围为6~12 mm,直径变化范围为1.2~2.0 mm,在微种植体头部的横槽内分别加载水平力（HF）和复合力（ CF）,观察长度和直径同时变化对周围颌骨等效应力峰值（ Max EQV）及微种植体位移峰值（ Max DM）的影响。结果 在两种力的作用下,随着长度和直径的增加,颌骨 Max EQV和微种植体 Max DM均下降,当长度大于 9 mm时,各评估指标值较小且变化幅度较小。灵敏度分析显示,直径对评估指标的影响较大。在 CF作用下,直径对评估指标的影响较 HF作用下显著。结论 在本研究所设定的参数范围内,微种植体的长度应不超过 9 mm,运用微种植体对牙齿进行转矩控制时,其直径应超过1.2 mm。     

短种植体的长度和表面设计对骨界面应力分布的影响

目的：探讨短种植体表面设计和长度对种植体周围骨组织的影响,为指导短种植体临床应用和开发新产品提供理论依据。方法：建立12种包含不同长度和不同表面设计短种植体的上颌后区骨块三维有限元模型：V形螺旋设计、反支撑形螺旋设计、支撑形螺旋设计和鳍式非螺旋设计分别建立种植体长度为7 mm、6.0 mm和5.0mm模型,对所有模型进行垂直和侧向加载,分析比较周围骨组织的应力分布和Von-Mises应力峰值。结果：垂直加载时,鳍式非螺旋设计的应力分布最合理,在螺纹设计中6.0mm反支撑形表现出较好的应力分布。侧向加载时,在同一长度下,鳍式非螺旋设计的应力分布最佳。结论：短种植体表面设计以鳍式非螺旋设计最佳,在螺纹设计中,反支撑形的应力分布更合理,应避免应用V形螺旋表面设计;螺纹表面设计的短种植体长度不应小于6mm;鳍式非螺旋设计的短种植体长度可以更小,甚至可以小于5mm。     

微型种植体长度对骨界面应力分布的影响

目的 探讨微型种植体长度对骨组织内应力分布的影响.方法建立直径1.6mm,长度分别为6、8、10、12 mm的种植体-下颌骨三维有限元模型,垂直植入种植体,给以1.96 N的水平向前及前上方向的载荷,记录并分析不同情况下的应力分布.结果 种植体水平向前载荷的应力峰值范围为3.500～3.765 MPa,位移峰值范围为1...     

微螺钉型种植体支抗长度及直径对应力分布影响的三维有限元研究

目的探索微螺钉型种植体支抗的长度及直径对种植体周围骨组织内应力分布的影响。方法建立简单的上颌骨及不同长度直径的微螺钉型种植体的三维有限元模型,模拟临床实际情况,记录不同尺寸的种植体在相同的加载条件下周围骨组织内应力分布的情况,并进行比较。结果随着种植体直径的增加,骨组织内的应力明显降低;种植体长度的增加对降低应力没有明显作用。结论在所研究的尺寸范围内,种植体的直径对应力分布有重要影响,而种植体的长度对应力分布影响不大。     

眶部种植体长度对骨界面应力影响的三维有限元研究

目的 探讨不同长度的眶部种植体对骨界面应力分布的影响。方法 建立直径3.75 mm,长度分别为3、4、6、10 mm的眶部种植体-颅颌面骨三维有限元模型,分别给予沿种植体轴向和与轴向成45°的载荷,载荷大小20 N,记录两种方向载荷下种植体及骨界面的Von-Mises应力峰值和位移峰值,分析其应力分布。结果 施加沿种植体轴向载荷时,种植体周围应力集中于根部,种植体受力大于骨面;施加与轴向成45°载荷时,应力集中于种植体颈部与第一螺纹之间,种植体受力大于骨面。施加两个方向的载荷时,3 mm种植体的应力峰值明显大于其他长度种植体,而位移峰值无明显变化。在相同长度下,施加沿种植体轴向载荷时的应力峰值及位移峰值均明显低于与轴向成45°载荷时,载荷方式对界面应力分布有明显的影响。结论 临床上尽量选择4 mm以上的眶部种植体;应用3 mm种植体时,应选择骨密质较厚的区域植入。     

8mm种植体骨内应力分布的三维有限元研究

目的 探讨在不同骨质条件中、达到骨整合时(40%的骨结合率),不同直径的8 mm种植体骨界面应力分布的变化规律,为短种植体的临床应用提供一定的参考和实验依据.方法 采用三维有限元方法分析6种不同直径的8 mm种植体在Ⅰ~Ⅳ类骨质条件中,受垂直和侧向力时,种植体骨界面的应力值大小及分布规律.结果 在~Ⅳ类骨质中,无论垂直或是斜向加载,应力值随着种植体直径增加,呈现减小的趋势.种植体直径3.3～5 mm时,最大应力值大小变化较为明显(曲率约为-1);种植体直径5.5～7.1mm时,变化趋于平缓(曲率接近0).另一方面,随着骨质密度降低,种植体骨界面的最大应力逐渐增大:Ⅳ类>Ⅲ类>Ⅱ类>Ⅰ类.在Ⅰ、Ⅱ类骨质中最大应力分布接近,Ⅲ、Ⅳ类骨质最大应力分布相近.结论 在临床应用短种植体时,可尽量选择较粗直径的种植体(直径3.3~5 mm),但当种植体直径足够大时(直径大于5.5 mm),再增加种植体直径对临床效果的改善不明显;实验结果显示,Ⅲ、Ⅳ类骨质时的应力值远大于Ⅰ、Ⅱ类骨质,提示在临床实践中,可以将Ⅲ、Ⅳ类的骨质通过骨挤压、骨移植等方式来提高骨密度,以保证远期成功率.     

两类传感器对种植体共振频率测量值影响的三维有限元研究

研究背景：共振频率法被认为是目前相对理想的测量种植体稳定性的方法。共振频率仪的测量传感器分为L型传感器和无线式铝杆传感器两类,然而,目前种植领域尚不清楚这两类传感器所测量的种植体共振频率值有何异同。目的：采用三维有限元法研究在不同骨质类型和不同种植体长度情况下,L型传感器和铝杆传感器两种设计对种植体共振频率测量值的影响。方法：（1）建立种植体-传感器-下颌磨牙区骨块三维有限元模型（ANSYS5.6软件）。种植体尺寸：直径固定为4.0mm,长度分4个等级：8.0mm、10.0mm、12.0mm和14.0mm;传感器分为两类：L型（高度22.0mm）和铝杆型（高度11.5mm）;模拟了3种骨质类型,即D2、D3和D4骨质。（2）在本质上,种植体一阶弯曲振动模态下的固有频率与共振频率仪所测量的共振频率相同,因此本研究直接采用有限元软件计算不同参数条件下种植体-骨块复合体的一阶固有频率。结果：（1）L型传感器组种植体的频率值在3763～4464Hz之间（平均4235Hz）,而铝杆模型种植体的频率值在9192～10002Hz之间（平均9708Hz）。（2）骨质由D4变为D2时,L型传感器组种植体的频率值增加百分比在12.7～16.7%之间（平均14.9%）,铝杆传感器组的增加百分比在7.4～8.5%之间（平均7.9%）。（3）对于L型传感器组而言,长度增加其频率值逐渐增加,14.0mm与8.0mm相比,频率值平均增幅为3.2%,对于铝杆传感器而言,D3骨质模型的频率值随长度增加而增加,在D4和D2骨质条件下,频率值呈先升后降（变化幅度较小）。（4）在D3骨质情况下,L型传感器测量值和铝杆传感器测量值之间存在线性相关,具有显著性（Pearson相关系数r=0.996,P=0.004）;在D4骨质情况下,L型传感器测量值和铝杆传感器测量值之间存在负相关关系,但是没有统计意义（r=-0.846,P〉0.05）;在D2骨质情况下,两组数值存在正相关关系,但同样没有统计意义（r=0.736,P〉0.05）。结论：在相同骨质类型、相同种植体尺寸条件下,L型传感器模型的频率值远小于铝杆传感器模型的频率值;L型传感器反映骨质变化的灵敏度高于铝杆传感器;在D3骨质条件下,两种传感器均能反映出测量值随长度增加而增加这一趋势     

Implant–Bone Interface Stress Distribution in Immediately Loaded Implants of Different Diameters: A Three-Dimensional Finite Element Analysis

Purpose: To establish a 3D finite element model of a mandible with dental implants for immediate loading and to analyze stress distribution in bone around implants of different diameters. Materials and Methods: Three mandible models, embedded with thread implants (ITI, Straumann, Switzerland) with diameters of 3.3, 4.1, and 4.8 mm, respectively, were developed using CT scanning and self‐developed Universal Surgical Integration System software. The von Mises stress and strain of the implant–bone interface were calculated with the ANSYS software when implants were loaded with 150 N vertical or buccolingual forces. Results: When the implants were loaded with vertical force, the von Mises stress concentrated on the mesial and distal surfaces of cortical bone around the neck of implants, with peak values of 25.0, 17.6 and 11.6 MPa for 3.3, 4.1, and 4.8 mm diameters, respectively, while the maximum strains (5854, 4903, 4344 μ?) were located on the buccal cancellous bone around the implant bottom and threads of implants. The stress and strain were significantly lower (p < 0.05) with the increased diameter of implant. When the implants were loaded with buccolingual force, the peak von Mises stress values occurred on the buccal surface of cortical bone around the implant neck, with values of 131.1, 78.7, and 68.1 MPa for 3.3, 4.1, and 4.8 mm diameters, respectively, while the maximum strains occurred on the buccal surface of cancellous bone adjacent to the implant neck, with peak values of 14,218, 12,706, and 11,504 μm, respectively. The stress of the 4.1‐mm diameter implants was significantly lower (p < 0.05) than those of 3.3‐mm diameter implants, but not statistically different from that of the 4.8 mm implant. Conclusions: With an increase of implant diameter, stress and strain on the implant–bone interfaces significantly decreased, especially when the diameter increased from 3.3 to 4.1 mm. It appears that dental implants of 10 mm in length for immediate loading should be at least 4.1 mm in diameter, and uniaxial loading to dental implants should be avoided or minimized.     

种植体长度对天然牙-种植体联合修复体应力影响的研究

目的:建立天然牙-种植体联合支持固定桥的三维有限元模型.探讨不同种植体长度对天然牙-种植体联合支持固定桥的修复体上部结构、天然牙等应力分布的影响.方法:对模型施加200N垂直向集中的力和200N颊舌向集中的力,运用CT扫描、三维有限元分析方法等手段,对比观察不同长度的种植体对天然牙及其修复体上部结构应力分布的影响.结果...     

密质骨厚度影响牙种植体稳定性的有限元固有频率分析

目的：用有限元方法研究密质骨厚度对牙种植体初期稳定性的影响。方法：建立牙种植体、局部下颌骨块三维有限元模型,利用ABAQUS有限元软件,分析不同密质骨厚度对种植体颊舌向、轴向一阶振动固有频率的影响。结果：随着密质骨厚度由缺如逐渐增加至3．0mm,种植体颊舌向、轴向振动的固有频率值均逐渐增加,其中颊舌向固有频率最大增幅达97．61％,而轴向固有频率最大值仅增加了11．06％。结论：种植体周密质骨厚度主要增加了种植体颊舌向稳定性,而对种植体轴向稳定性的增加有限。     

种植体根尖部与上颌窦底皮质骨的关系对上颌后牙区种植影响的三维有限元分析

目的    利用三维有限元分析方法评估种植体根尖部与上颌窦底皮质骨的关系对上颌后牙区种植的生物力学影响。方法    应用计算机辅助设计（computer assisted design,CAD）软件建立标准种植体及上颌后牙区三维有限元模型（M1 ~ M6）,皮质骨厚度均为1 mm,依据牙槽骨高度不同（10 ~ 14 mm）,种植体根尖部与上颌窦底皮质骨的关系如下。M1：种植体根尖部穿通上颌窦底皮质骨（窦底皮质骨的上表面与种植体根尖部位于同一平面）;M2：种植体根尖部进入窦底皮质骨厚度的一半;M3：种植体根尖部恰好接触窦底皮质骨的下表面;M4 ~ M6：种植体根尖部分别距离窦底皮质骨的下表面1、2、3 mm。采用129 N斜向加载,分别置于即刻负载与常规负载条件下,计算其应力分布、最大von Mises应力、种植体的最大位移和共振频率。结果    除M1即刻负载外,最大von Mises应力均集中于种植体颈部周围的牙槽嵴顶皮质骨表面。无论即刻负载或常规负载下,种植体根尖部进入或穿通窦底皮质骨时,牙槽嵴顶皮质骨的最大von Mises应力降低,窦底皮质骨的最大von Mises应力增加,种植体的轴向共振频率显著增加,颊舌向共振频率显著降低。即刻负载条件下,当种植体进入或穿通窦底皮质骨时,其最大位移尤其是根尖部的最大位移小于其他情况下的最大位移。常规负载条件下,种植体颈部与根尖部的最大位移几乎不受种植体根尖部位置的影响。结论    种植体根尖部与上颌窦底皮质骨的相对位置关系对种植体周围组织的应力分布、种植体的最大位移以及共振频率均有一定影响。种植体根尖部进入或穿通上颌窦底皮质骨有利于改善应力分布,减少种植体根尖部的位移,增加种植体的稳定性,尤其在即刻负载下作用显著。     

种植牙即刻负载与延期负载的生物力学三维有限元分析

目的比较即刻负载和延期负载对种植体骨界面生物力学分布的影响。方法采用CT扫描和自主开发的USIS软件建模,用有限元法计算分析即刻负载和延期负载时种植体骨界面的应力、应变及种植体的位移。结果即刻负载时种植体骨界面的VonMises应力稍小于延期负载,均集中于种植体颈部骨皮质,底部骨松质次之;但VonMises应变有较明显的增加,均集中于种植体底部骨松质和螺纹部位;种植体的位移较延期负载略有增大。即刻负载种植体和延期负载种植体在受到颊舌向力时,VonMises应力、应变及位移均有不同程度的增加。结论即刻负载时种植体骨界面的生物力学分布规律与延期负载时相似,受到侧向力时应力、应变增大。种植牙即刻负载技术是可行的。     

Comparative evaluation of peri-implant stress distribution in implant protected occlusion and cuspally loaded occlusion on a 3 unit implant supported fixed partial denture: A 3D finite element analysis study

PURPOSETo assess peri-implant stress distribution using finite element analysis in implant supported fixed partial denture with occlusal schemes of cuspally loaded occlusion and implant protected occlusion.MATERIALS AND METHODSA 3-D finite element model of mandible with D2 bone with partially edentulism with unilateral distal extension was made. Two Ti alloy identical implants with 4.2 mm diameter and 10 mm length were placed in the mandibular second premolar and the mandibular second molar region and prosthesis was given with the mandibular first molar pontic. Vertical load of 100 N and and oblique load of 70 N was applied on occlusal surface of prosthesis. Group 1 was cuspally loaded occlusion with total 8 contact points and Group 2 was implant protected occlusion with 3 contact points.RESULTSIn Group 1 for vertical load , maximum stress was generated over implant having 14.3552 Mpa. While for oblique load, overall stress generated was 28.0732 Mpa. In Group 2 for vertical load, maximum stress was generated over crown and overall stress was 16.7682 Mpa. But for oblique load, crown stress and overall stress was maximum 22.7561 Mpa. When Group 1 is compared to Group 2, harmful oblique load caused maximum overall stress 28.0732 Mpa in Group 1.CONCLUSIONIn Group 1, vertical load generated high implant stress, and oblique load generated high overall stresses, cortical stresses and crown stresses compared to vertical load. In Group 2, oblique load generated more overall stresses, cortical stresses, and crown stresses compared to vertical load. Implant protected occlusion generated lesser harmful oblique implant, crown, bone and overall stresses compared to cuspally loaded occlusion.     

Effect of diameter and length on stress distribution of the alveolar crest around immediate loading implants

Background: Many clinical observations have shown that immediate loading is indicated when the stabilization of the bone/implant is optimal and when the estimated loads are not excessively high. Nonetheless, more experimental studies are needed to consider the immediate loading protocol as a safe procedure. Mechanical analysis using the finite element (FE) method analysis has been employed by many authors to understand the biomechanical behavior around dental implants. Purpose: This study was to evaluate the effect of the diameter and length on the stress and strain distribution of the crestal bone around implants under immediate loading. Materials and Methods: By an ad hoc automatic mesh generator, high‐quality FE models of complete range mandible was constructed from computer tomography, with three Straumann (Straumann Institute, Waldenburg, Switzerland) implants of various sizes embedded in the anterior zone. The implant diameter ranged from 3.3 to 4.8 mm, and length ranged from 6 to 14 mm, resulting in seven designs. The implant–bone interface was simulated by nonlinear frictional contact algorithm. For each design, vertical and oblique loadings of 150 N were applied, respectively, to each implant, and stresses and strains in the surrounding cortical bone were evaluated. Results: The biomechanics analysis provided results that the oblique loading would induce significantly higher interfacial stresses and strains than the vertical loading, while the intergroup stress difference significant levels was evaluated using t‐tests method and the level of significance (.05) that was accepted for significance. Under both loadings, the maximal values were recorded in the 3.3 (diameter) × 10 (length) mm implant configuration, whose mean and peak values were both higher than that of others with significant statistical differences. The second maximal one is 4.1 × 6 mm configuration, and the minimal stresses were recorded in 4.8 × 10 mm configuration, whose strains were also near to lowest. Conclusions: Increasing the diameter and length of the implant decreased the stress and strain on the alveolar crest, and the stress and strain values notably increased under buccolingual loading as compared with vertical loading, but diameter had a more significant effect than length to relieve the crestal stress and strain concentration.     

平台转换种植体周围应力分布的三维有限元分析

目的:分析平台转换种植体周围的力学分布特点。方法:利用CATIA画图软件,建立种植体支持的上颌第一前磨牙三维模型,分析垂直向和斜向加载条件下平齐对接(PM)和平台转换(PS)种植体周围的应力分布差异;比较不同材料基台平台转换冠修复后种植体周围的应力分布差异。结果:①PS型种植体在垂直加载和斜向加载时种植体周围骨组织内最大von Mises应力值均较PM型小。②不同材料基台种植体周围应力分布云图相似,应力均集中在种植体颈部。结论:①PS种植体周围骨组织最大应力值较PM种植体小,但基台、中央螺丝、种植体的应力增大。②斜向加载较垂直向加载种植体周围应力值大大增加,特别是基台及种植体部位较为明显。③基台材料对种植体周围应力值无明显影响。     

Evaluation of Design Parameters of Dental Implant Shape, Diameter and Length on Stress Distribution: A Finite Element Analysis

The aim was to evaluate the design parameters of dental implants shape, diameter and length on stress distribution by finite element analysis (FEA).The objectives of the study was to compare the influence of stress distribution in the implants of screw-vent tapered and parallel design by varying the implant diameter with a standard implant length. Six dental implant models have been simulated three-dimensionally. The influence of diameter and length on stress distribution was evaluated by Group I: for screw-vent tapered design (Zimmer Dental Implant Carlsbad, CA, USA) (1) Dental implant model with diameter 3.7 mm and length 13 mm. (2) Dental implant model with diameter 4.1 mm and length 13 mm. (3) Dental implant model with diameter 4.7 mm and length 13 mm. Group II: for parallel design (Zimmer Dental Implant Carlsbad, CA, USA) (4) Dental implant model with diameter 3.7 mm and length 13 mm. (5) Dental implant model with diameter 4.1 mm and length 13 mm. (6) Dental implant model with diameter 4.7 mm and length 13 mm. The 3-D model of the implant was created in the pro-e wildfire 4.0 software by giving various commands. This model was imported to the ANSYS software through IGES (initial graphic exchange specification) file for further analysis. All six models were loaded with a force of 17.1, 114.6 and 23.4 N in a lingual, an axial and disto-mesial direction respectively, simulating average masticatory force in a natural oblique direction, to analyze the stress distribution on these implants. The increase in implant diameter in Group I and Group II from 3.7 to 4.1 mm and from 4.1 to 4.7 mm with constant 13 mm length for screw-vent tapered and parallel design implant resulted in a reduction in maximum value of Von Mises stress in the bone surrounding the implant was statistically significant at 5% level done by student “t” test. The overall maximum value of Von Mises stress was decreased in parallel design implant diameter of 4.7 mm with constant length of 13 mm when compared to screw-vent tapered design implant samples. The results of the FEA computation depend on many individual factors including material properties, boundary conditions interface definition and also on the overall approach to the model. The results depicted that the tapered shape implant design exhibited higher stress levels in bone than the parallel shaped implant design which seemed to be distributing stresses more evenly. The application of a 3-D model simulation with the non-symmetric loading by the masticatory force on a dental implant resulted in a more satisfactory modeling of “clinical reality” than that achieved with 2-D models used in other studies.