Root fractures in seniors: Consequences of acute embrittlement of dentin
Root fractures in seniors: Consequences of acute embrittlement of dentin
复制标题
老年人牙根折裂：牙本质急性脆化的后果
DOI：
10.1016/j.dental.2020.08.008
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发表时间：
2020
期刊：
影响因子：
5
通讯作者：
Arola, D.
中科院分区：
文献类型：
--
作者：
Yan, W.;Chen, H.;Fernandez-Arteaga, J.;Paranjpe, A.;Zhang, H.;Arola, D.
随着年龄的增长，牙本质的微观结构发生了不可逆的变化，其中包括小管腔逐渐被矿物质填充。这一过程被称为牙硬化，始于牙根尖，向冠状方向发展，并与牙本质抗骨折能力下降有关。目的确定i)随年龄增长管间牙本质的年龄相关变化，特别是根内的变化；ii)有生命牙和无髓牙（即非有生命牙）之间年龄相关退化的差异。方法在扫描模式下对青年和老年人牙齿的管间和管周牙本质进行纳米动态力学分析（nanoDMA）。对未修复牙和已根管治疗牙（非生命牙）的复合模量、损失模量、储存模量以及tan δ参数进行评估。结果根管间牙本质的动态模量随年龄的增长有明显的变化，其中以根尖三分之一的动态模量最为显著。管间牙本质的储存模量（用于量化纯弹性变形阻力）在整个牙根长度上，老年生命牙和非生命牙的储存模量都明显大于年轻牙（p < 0.0005）。然而，量化粘性变形相对能力的tan delta参数在这两组中明显较低（p < 0.005）。根状牙本质随着时效发生脆化，包括粘性变形能力降低。顶部三分之一的退化程度最大。去除牙髓似乎会加速老化过程或加重降解程度。
Dentin undergoes irreversible changes in microstructure with aging that involve gradual filling of the tubule lumens with mineral. Known as dental sclerosis, this process begins at the root apex, progresses coronally, and is associated with a degradation in the resistance to fracture of dentin.ObjectiveTo determine i) age-related changes of intertubular dentin with aging, particularly within the root, and ii) the differences in age-related degradation between vital and pulpless (i.e. non-vital) teeth.MethodsWe performed nanoscopic dynamic mechanical analysis (nanoDMA) in scanning mode on the intertubular and peritubular dentin of teeth from young and old adults. The complex, loss and storage moduli, as well as the tan delta parameter were evaluated for teeth with no restorations and teeth with root canal treatment (non-vital).ResultsThere were significant changes in the dynamic moduli of intertubular dentin with age, which were most substantial in the apical third of the root. The storage modulus of the intertubular dentin, which quantifies the purely elastic resistance to deformation, was significantly (p < 0.0005) larger for both the old vital and non-vital teeth than that of the young teeth, over the entire root length. However, the tan delta parameter, which quantifies the relative capacity for viscous deformation, was significantly lower in these two groups (p < 0.005).SignificanceRadicular dentin undergoes an embrittlement with aging, involving reduced capacity for viscous deformation. The extent of degradation is largest in the apical third. Removal of the pulp appears to accelerate the aging process or compound the extent of degradation.