Departamento de Ingeniería Mecánica, Energética y de los Materiales, Universidad de Extremadura, 06006 Badajoz, Spain.
Department of Biology, Saint Michaels College, Colchester, VT 05439, USA.
Acta Biomater. 2015 Mar;14:146-53. doi: 10.1016/j.actbio.2014.11.047. Epub 2014 Dec 4.
It is hypothesized that microwear traces in natural tooth enamel can be simulated and quantified using microindentation mechanics. Microcontacts associated with particulates in the oral wear medium are modeled as sharp indenters with fixed semi-apical angle. Distinction is made between markings from static contacts (pits) and translational contacts (scratches). Relations for the forces required to produce contacts of given dimensions are derived, with particle angularity and compliance specifically taken into account so as to distinguish between different abrasives in food sources. Images of patterns made on human enamel with sharp indenters in axial and sliding loading are correlated with theoretical predictions. Special attention is given to threshold conditions for transition from a microplasticity to a microcracking mode, corresponding to mild and severe wear domains. It is demonstrated that the typical microwear trace is generated at loads on the order of 1N - i.e. much less than the forces exerted in normal biting - attesting to the susceptibility of teeth to wear in everyday mastication, especially in diets with sharp, hard and large inclusive intrinsic or extraneous particulates.
据推测，可使用微压痕力学来模拟和量化天然牙釉质中的微观磨损痕迹。将与口腔磨损介质中的颗粒相关联的微接触模拟为具有固定半顶角的尖锐压痕。区分了来自静态接触（凹痕）和平移接触（划痕）的标记。推导出了产生给定尺寸接触所需力的关系，特别考虑了颗粒的各向异性和顺应性，以便区分食物来源中的不同磨料。用尖锐压痕在轴向和滑动加载下在人牙釉质上制作的图案图像与理论预测相关联。特别关注从微塑性到微裂纹模式过渡的阈值条件，对应于轻度和重度磨损区域。结果表明，典型的微观磨损痕迹是在 1N 左右的载荷下产生的 - 即远小于正常咀嚼时施加的力 - 证明了牙齿在日常咀嚼中容易磨损的特性，尤其是在饮食中含有尖锐、坚硬和大的内在或外在颗粒时。
