Liu Qing, Dong Qianqian, Wen Yifeng, Shi Baoquan
Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an 710004, China.
Clinical Research Center of Shaanxi Province for Dental and Maxillofacial Diseases, College of Stomatology, Xi'an Jiaotong University, Xi'an 710004, China.
Materials (Basel). 2022 Mar 18;15(6):2246. doi: 10.3390/ma15062246.
Full-field measurements can provide a more complete description of the behavior of human whole tooth under load. To that end, in vitro experiments were carried out to measure the full-field buccal surface strains of human premolars free of caries and abrasion using digital image correlation (DIC). Experimental results show that both the value field and the orientation field of strains can be observed exactly, both of which contain a wealth of information. Furthermore, the strain distributions between the crown and the root of specimens were significantly different (p < 0.001). An interesting observation was a watershed at the cementoenamel junction (CEJ) which separates the orientation field of strains into two distinct parts; the watershed was also observed in the value field of strains in some specimens whose geometries changed obviously at the CEJ. Another interesting observation was that the minor strains increased linearly from cervical to apical regions in the root cementum. Experimental results also support the viewpoint that mechanisms of non-carious cervical lesions (NCCLs) may in part be due to the changing orientation of tensile strains, as well as their magnitude, and they also support the hypothesis that occlusal force can contribute to root fractures.
全场测量可以更全面地描述人类全牙在负载下的行为。为此，进行了体外实验，使用数字图像相关技术（DIC）测量无龋损和磨损的人类前磨牙颊面的全场应变。实验结果表明，应变的数值场和方向场均能被精确观测到，二者都包含丰富的信息。此外，标本冠部和根部之间的应变分布存在显著差异（p < 0.001）。一个有趣的发现是，在牙骨质釉质界（CEJ）处存在一个分水岭，它将应变方向场分为两个不同的部分；在一些在CEJ处几何形状明显变化的标本的应变数值场中也观察到了这个分水岭。另一个有趣的发现是，根牙骨质中的微小应变从颈部到根尖区域呈线性增加。实验结果还支持了以下观点：非龋性颈部病变（NCCLs）的机制可能部分归因于拉伸应变方向及其大小的变化，并且它们也支持了咬合力量会导致牙根骨折的假说。
