To evaluate the effect of restorative materials on stress distribution of endodontically treated teeth, the 3D models of an endodontically treated mand^ular first molar, restoration, and cement layer were created. Thr...To evaluate the effect of restorative materials on stress distribution of endodontically treated teeth, the 3D models of an endodontically treated mand^ular first molar, restoration, and cement layer were created. Three different materials （composite resin, ceramage and ceramic） were studied and two loading conditions （vertical and oblique load） were simulated. Mohr-Coulomb failure criterion of enamel, dentine, endocrown and cement were evaluated separately. It is indicated that under both loading conditions, the highest values of Mohr-Coulomb failure criterion were observed in Ceramage-restored group for remaining tooth structure while in ceramic-restored group for the restoration. Compared to composite resin and Ceramage, ceramic endocrown transferred less stress, namely was more protective to the tooth structure.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
目的:了解不同洞形深度对应用椅旁CAD/CAM制作的髓腔固位冠(endocrown)边缘和内部适合性的影响,以期为临床牙体预备提供参考。方法:制作三个不同深度相同聚合度的髓腔固位冠基准模型,并分别复制出12个超硬石膏模型,采用Cerec AC Blueca...目的:了解不同洞形深度对应用椅旁CAD/CAM制作的髓腔固位冠(endocrown)边缘和内部适合性的影响,以期为临床牙体预备提供参考。方法:制作三个不同深度相同聚合度的髓腔固位冠基准模型,并分别复制出12个超硬石膏模型,采用Cerec AC Bluecam扫描获取光学模型并制作修复体,粘结后,包埋、切割,利用三维测量系统测量髓腔固位冠边缘及内部粘接剂厚度并进行统计学分析。结果:三种洞形深度的髓腔固位冠边缘的粘接剂厚度均小于120μm,内部粘接剂的厚度均小于200μm;在边缘,3种洞形深度粘接剂的厚度两两比较差异均具有统计学意义(P<0.05);在轴牙合角处,粘接剂的厚度随着洞形深度的增加而增加,洞形深度为2mm和4mm时粘接剂的厚度差异具有统计学意义(P<0.05);在轴髓角处,洞形深度为3mm时与洞形深度为2mm和4mm时粘接剂厚度比较差异分别具有统计学意义(P<0.05);在牙合面肩台中点、轴壁和髓腔固位洞形底部,3种洞形深度粘接剂厚度两两比较差异均不具有统计学意义。除轴牙合角、轴壁和髓腔固位洞形底部,其他测量位点洞形深度为3mm时粘接剂的厚度最小。结论:基于本研究结果,应用椅旁CAD/CAM技术制作髓腔固位冠时,3种洞形深度的髓腔固位冠其边缘和内部适合性均能达到临床要求;洞形深度为3mm时其边缘和内部适合性优于深度为2mm和4mm时。展开更多
基金Founded by National Natural Science Foundation of China(No.51305306)Hubei Province Science and Technology Support Program(No.2013BCB025)Fundamental Research Funds for the Central University(No.2042014kf0274)
文摘To evaluate the effect of restorative materials on stress distribution of endodontically treated teeth, the 3D models of an endodontically treated mand^ular first molar, restoration, and cement layer were created. Three different materials （composite resin, ceramage and ceramic） were studied and two loading conditions （vertical and oblique load） were simulated. Mohr-Coulomb failure criterion of enamel, dentine, endocrown and cement were evaluated separately. It is indicated that under both loading conditions, the highest values of Mohr-Coulomb failure criterion were observed in Ceramage-restored group for remaining tooth structure while in ceramic-restored group for the restoration. Compared to composite resin and Ceramage, ceramic endocrown transferred less stress, namely was more protective to the tooth structure.
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。
文摘目的:了解不同洞形深度对应用椅旁CAD/CAM制作的髓腔固位冠(endocrown)边缘和内部适合性的影响,以期为临床牙体预备提供参考。方法:制作三个不同深度相同聚合度的髓腔固位冠基准模型,并分别复制出12个超硬石膏模型,采用Cerec AC Bluecam扫描获取光学模型并制作修复体,粘结后,包埋、切割,利用三维测量系统测量髓腔固位冠边缘及内部粘接剂厚度并进行统计学分析。结果:三种洞形深度的髓腔固位冠边缘的粘接剂厚度均小于120μm,内部粘接剂的厚度均小于200μm;在边缘,3种洞形深度粘接剂的厚度两两比较差异均具有统计学意义(P<0.05);在轴牙合角处,粘接剂的厚度随着洞形深度的增加而增加,洞形深度为2mm和4mm时粘接剂的厚度差异具有统计学意义(P<0.05);在轴髓角处,洞形深度为3mm时与洞形深度为2mm和4mm时粘接剂厚度比较差异分别具有统计学意义(P<0.05);在牙合面肩台中点、轴壁和髓腔固位洞形底部,3种洞形深度粘接剂厚度两两比较差异均不具有统计学意义。除轴牙合角、轴壁和髓腔固位洞形底部,其他测量位点洞形深度为3mm时粘接剂的厚度最小。结论:基于本研究结果,应用椅旁CAD/CAM技术制作髓腔固位冠时,3种洞形深度的髓腔固位冠其边缘和内部适合性均能达到临床要求;洞形深度为3mm时其边缘和内部适合性优于深度为2mm和4mm时。
