AIM: To study the root fracture resistance after root canal preparation with Ni-Ti rotary instruments and stainless hand instruments by means of meta-analysis.METHODS: Literature was researched in CNKI and CBMDisc, Pu...AIM: To study the root fracture resistance after root canal preparation with Ni-Ti rotary instruments and stainless hand instruments by means of meta-analysis.METHODS: Literature was researched in CNKI and CBMDisc, Pub Med, CALIS, Proquest, Web of Scienceand 11 kinds of Chinese or English dentistry journals. Retrieval time on Internet was in all years and hand retrieval time was from January 2013 to October 2013. The literatures were selected through reading abstracts and full texts by two reviewers independently and Revman 5 software was used to analysize the literature. RESULTS: Six articles met the inclusion criteria. According to Meta-analysis of tooth root bending properties, total standardized mean difference(SMD) was 0.63(95%CI:-0.24-1.50, P > 0.05). That indicated there was no statistically significant between the two groups. Subgroup analysis was carried out. SMD were 2.22(95%CI: 0.23-4.20, P < 0.05) and-0.61(95%CI:-1.05--0.17, P < 0.05) when the premolar teeth with a single canal or the mesiobuccal roots of molars were used as the materials for tests to compare the effects of different root canal preparation methods on root fracture resistance. That only indicated that there were statistically significant in two subgroups.CONCLUSION: In vitro experiments, the effects on the fracture resistance of root had no statistical difference with Ni-Ti rotary instruments and stainless steel hand instruments in root canal preparation.展开更多
目的比较不同颊舌侧剩余牙体组织厚度的下颌第一磨牙根管治疗后,两种不同修复方式受力后的修复体、剩余牙体组织与黏接界面的应力大小及分布。方法根据颊舌侧牙体组织剩余量设计三组不同的下颌第一磨牙根管治疗后模型,在此基础上模拟FO...目的比较不同颊舌侧剩余牙体组织厚度的下颌第一磨牙根管治疗后,两种不同修复方式受力后的修复体、剩余牙体组织与黏接界面的应力大小及分布。方法根据颊舌侧牙体组织剩余量设计三组不同的下颌第一磨牙根管治疗后模型,在此基础上模拟FO和EC的牙体预备及修复体的制备,生成6组不同的下颌第一磨牙根管治疗后FO和EC模型:A1组采用FO修复,颊舌侧剩余牙体组织厚度为2mm;A2组采用FO修复,颊舌侧剩余牙体组织厚度为3mm;A3组采用FO修复,颊舌侧剩余牙体组织厚度为4mm;B1组采用EC修复,颊舌侧剩余牙体组织厚度为2mm;B2组采用EC修复,颊舌侧剩余牙体组织厚度为3mm;B3组采用EC修复,颊舌侧剩余牙体组织厚度为4mm。施加垂直向及斜向载荷,记录两种加载模式下不同修复形式的修复体、剩余牙体组织与黏接界面的应力大小及分布。结果两种加载模式下,修复体等效应力分布均集中在加载点周围,牙本质等效应力均集中在牙齿颈部,全覆盖式高嵌体组修复体-牙体树脂界面最大主应力(maximum principal stress,MPS)集中在洞型底壁和轴壁线角处,髓腔固位冠组修复体-牙体树脂界面MPS集中在髓腔固位洞型的底壁线角处。同一颊舌侧牙体组织厚度的模型,除斜向加载时髓腔固位冠的修复体等效应力峰值大于全覆盖式高嵌体组的修复体等效应力峰值,其余条件下全覆盖式高嵌体的各项观察指标峰值均大于髓腔固位冠。结论髓腔固位冠更能保护根管治疗后牙体组织,建议在根管治疗后选择髓腔固位冠修复。展开更多
背景:利用三维有限元法的变分原理和加权技术,可将具有复杂形态结构的人类牙齿模型化,有利于了解动态过程中牙体硬组织和修复体的应力分布。目的:综合分析近年来口腔领域的国内外学者对修复体生物力学的三维有限元研究状况,特别是金属...背景:利用三维有限元法的变分原理和加权技术,可将具有复杂形态结构的人类牙齿模型化,有利于了解动态过程中牙体硬组织和修复体的应力分布。目的:综合分析近年来口腔领域的国内外学者对修复体生物力学的三维有限元研究状况,特别是金属基底冠、瓷层厚度、根管预备及充填对牙体应力变化的影响。方法:由第一作者应用计算机检索1993年4月至2012年9月PubMed数据库及2001至2008年中文期刊全文数据库、维普数据库有关三维有限元法分析金属基底冠、瓷层厚度、根管预备及充填方式对牙体应力变化影响的文章,英文检索词为"porcelain-fused-to-metal,finite element method,stress analysis,root canal",中文检索词为"烤瓷熔附金属全冠,三维有限元法,应力分析,根管"。排除重复性研究及Meta分析,共保留40篇文献进行综合分析。结果与结论:三维有限元法在口腔医学中对建立高真实度和精确度的模型有着重要的意义,因此对牙体的根管治疗和治疗后修复提供了有效的生物力学信息。有关牙体与修复体在应对咀嚼作用时的应力分布在不断地探索与研究。文章总结了口腔领域国内外学者利用有限元法分析桩核冠修复体的应力变化,为将来进一步的研究提供了参考和借鉴。结果显示,三维有限元法能够建立具有非线性,各向异性等生物力学特征的三维有限元模型,能够逐渐完善其从静态分析到动态分析的转变,以真正达到精确模拟口腔生物学形态及牙齿咀嚼功能的目的。展开更多
文摘AIM: To study the root fracture resistance after root canal preparation with Ni-Ti rotary instruments and stainless hand instruments by means of meta-analysis.METHODS: Literature was researched in CNKI and CBMDisc, Pub Med, CALIS, Proquest, Web of Scienceand 11 kinds of Chinese or English dentistry journals. Retrieval time on Internet was in all years and hand retrieval time was from January 2013 to October 2013. The literatures were selected through reading abstracts and full texts by two reviewers independently and Revman 5 software was used to analysize the literature. RESULTS: Six articles met the inclusion criteria. According to Meta-analysis of tooth root bending properties, total standardized mean difference(SMD) was 0.63(95%CI:-0.24-1.50, P > 0.05). That indicated there was no statistically significant between the two groups. Subgroup analysis was carried out. SMD were 2.22(95%CI: 0.23-4.20, P < 0.05) and-0.61(95%CI:-1.05--0.17, P < 0.05) when the premolar teeth with a single canal or the mesiobuccal roots of molars were used as the materials for tests to compare the effects of different root canal preparation methods on root fracture resistance. That only indicated that there were statistically significant in two subgroups.CONCLUSION: In vitro experiments, the effects on the fracture resistance of root had no statistical difference with Ni-Ti rotary instruments and stainless steel hand instruments in root canal preparation.
文摘目的比较不同颊舌侧剩余牙体组织厚度的下颌第一磨牙根管治疗后,两种不同修复方式受力后的修复体、剩余牙体组织与黏接界面的应力大小及分布。方法根据颊舌侧牙体组织剩余量设计三组不同的下颌第一磨牙根管治疗后模型,在此基础上模拟FO和EC的牙体预备及修复体的制备,生成6组不同的下颌第一磨牙根管治疗后FO和EC模型:A1组采用FO修复,颊舌侧剩余牙体组织厚度为2mm;A2组采用FO修复,颊舌侧剩余牙体组织厚度为3mm;A3组采用FO修复,颊舌侧剩余牙体组织厚度为4mm;B1组采用EC修复,颊舌侧剩余牙体组织厚度为2mm;B2组采用EC修复,颊舌侧剩余牙体组织厚度为3mm;B3组采用EC修复,颊舌侧剩余牙体组织厚度为4mm。施加垂直向及斜向载荷,记录两种加载模式下不同修复形式的修复体、剩余牙体组织与黏接界面的应力大小及分布。结果两种加载模式下,修复体等效应力分布均集中在加载点周围,牙本质等效应力均集中在牙齿颈部,全覆盖式高嵌体组修复体-牙体树脂界面最大主应力(maximum principal stress,MPS)集中在洞型底壁和轴壁线角处,髓腔固位冠组修复体-牙体树脂界面MPS集中在髓腔固位洞型的底壁线角处。同一颊舌侧牙体组织厚度的模型,除斜向加载时髓腔固位冠的修复体等效应力峰值大于全覆盖式高嵌体组的修复体等效应力峰值,其余条件下全覆盖式高嵌体的各项观察指标峰值均大于髓腔固位冠。结论髓腔固位冠更能保护根管治疗后牙体组织,建议在根管治疗后选择髓腔固位冠修复。
文摘背景:利用三维有限元法的变分原理和加权技术,可将具有复杂形态结构的人类牙齿模型化,有利于了解动态过程中牙体硬组织和修复体的应力分布。目的:综合分析近年来口腔领域的国内外学者对修复体生物力学的三维有限元研究状况,特别是金属基底冠、瓷层厚度、根管预备及充填对牙体应力变化的影响。方法:由第一作者应用计算机检索1993年4月至2012年9月PubMed数据库及2001至2008年中文期刊全文数据库、维普数据库有关三维有限元法分析金属基底冠、瓷层厚度、根管预备及充填方式对牙体应力变化影响的文章,英文检索词为"porcelain-fused-to-metal,finite element method,stress analysis,root canal",中文检索词为"烤瓷熔附金属全冠,三维有限元法,应力分析,根管"。排除重复性研究及Meta分析,共保留40篇文献进行综合分析。结果与结论:三维有限元法在口腔医学中对建立高真实度和精确度的模型有着重要的意义,因此对牙体的根管治疗和治疗后修复提供了有效的生物力学信息。有关牙体与修复体在应对咀嚼作用时的应力分布在不断地探索与研究。文章总结了口腔领域国内外学者利用有限元法分析桩核冠修复体的应力变化,为将来进一步的研究提供了参考和借鉴。结果显示,三维有限元法能够建立具有非线性,各向异性等生物力学特征的三维有限元模型,能够逐渐完善其从静态分析到动态分析的转变,以真正达到精确模拟口腔生物学形态及牙齿咀嚼功能的目的。
