Multiple analyses on mechanisms of root fracture in endodontically treated teeth

根管治疗牙根折机制的多重分析

• 批准号: 16390546
• 负责人: HAYASHI Mikako
• 金额: $ 8.7万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16390546/
• 关键词: post-core restoration; root fracture; fatigue fracture; fractography; resin composite; ceramics; fiber post; endodontically treated teeth; 水中環境; 亀裂進展; フラクトグラフィー; レジンコア; 接着性レジンセメント; 破壊抵抗性

Extracted human upper premolars were restored with a fiber post, prefabricated metallic post or cast metallic post-core. Teeth with full crown preparations without post-core restorations served as a control. All teeth were restored with full coverage crowns. A 90-degree vertical or 45-degree oblique load was applied to the restored teeth with a crosshead speed of 0.5 mm/min, and the fracture loads and mode of fracture were recorded. Fatigue fracture tests were conducted by applying sinusoidal cyclic loads to restored teeth from vertical or oblique directions. Fatigue limits for each restoration were calculated using the staircase approach.Under the condition of vertical loading, the fracture load of teeth restored with the cast metallic post-cores was greatest among the groups. All fractures in teeth restored with all types of post-core systems propagated in the middle portions of roots, including the apices of the posts. Under the condition of oblique loading, the fracture load of teeth restored with pre-fabricated metallic posts was significantly smaller than that in other groups. Two-thirds of fractures in the fiber post group propagated within the cervical area, while most fractures in other groups extended beyond the middle of the roots. Fatigue fracture resistance of teeth with different restoration methods presented identical patterns in static fracture resistance tests. Fatigue limits of teeth restored with fiber and metallic posts presented 73% of static fracture loads under vertical loading, and 48 and 46% under oblique loading.From the results of the present investigations, it was concluded that under conditions of vertical and oblique loadings, the combination of a fiber post and composite resin core with a full cast crown is most protective to the remaining tooth structure.

采用纤维桩、预制金属桩和铸造金属桩核修复离体上颌前磨牙。无桩核置换的全冠预备牙作为对照。所有患牙均行全冠修复。以0.5mm/min的十字头速度向修复体施加90 °垂直或45 °倾斜载荷，记录断裂载荷和断裂模式。疲劳断裂试验通过施加正弦循环载荷从垂直或斜向修复牙齿进行。采用阶梯法计算各修复体的疲劳极限，在垂直载荷条件下，铸造金属桩核修复体的断裂载荷最大。所有类型桩核系统修复的牙折均发生在牙根的中部，包括桩尖。在斜向加载条件下，预制金属桩修复牙的断裂载荷明显小于其他组。纤维桩组中三分之二的骨折在颈部区域内扩散，而其他组中的大多数骨折延伸到牙根中部以外。在静态抗折强度试验中，不同修复方法的牙体抗疲劳断裂强度表现出相同的规律。纤维桩和金属桩修复的牙齿的疲劳极限在垂直载荷下为静态断裂载荷的73%，在斜向载荷下为48%和46%，从目前的调查结果可以得出结论，在垂直和斜向载荷的条件下，纤维桩和复合树脂核与全铸造冠的组合是最保护剩余的牙齿结构。

项目成果

Fracture resistance of pulpless teeth restored with post-cores and crowns

• DOI: 10.1016/j.dental.2005.03.017
• 发表时间: 2006-05-01
• 期刊: DENTAL MATERIALS
• 影响因子: 5
• 作者: Hayashi, M;Takahashi, Y;Ebisu, S
• 通讯作者: Ebisu, S

Restoring of erosion associated with gastroesophageal reflux result from anorexia nervosa using ceramic laminate veneers : a case report

使用陶瓷层压贴面恢复与神经性厌食症引起的胃食管反流相关的糜烂：病例报告

• 发表时间: 2007
• 期刊: Operative Dentistry (in press)
• 作者: Takeshige F;Hayashi M. et al.;Hayashi M. et al.
• 通讯作者: Hayashi M. et al.

The accuracy of electrical method for microleakage evaluation by a three-dimensional analysis

三维分析电法微泄漏评估的准确性

• 发表时间: 2007
• 期刊: J Dent 35・3
• 作者: 宮崎隆;小林千尋;他;Iwami Y et al.
• 通讯作者: Iwami Y et al.

Fatigue of tooth-colored restoratives in aqueous environments

水环境中牙色修复体的疲劳

• 发表时间: 2007
• 期刊: Dental Materials Journal 26巻・1号
• 作者: Takeshige F;Hayashi M. et al.
• 通讯作者: Hayashi M. et al.

Influence of explorer tip diameter identifying restoration margin discrepancies.

探尖直径对识别修复体边缘差异的影响。

• 发表时间: 2005
• 期刊: Journal of Dentistry 33巻
• 作者: Iwami Y;Hayashi M;Takeshige F et al.;Iwami Y. et al.;Iwami Y. et al.;Hayashi M.et al.;Hayashi M.et al.;Hayashi M.et al.
• 通讯作者: Hayashi M.et al.