Abstract：
Edge chipping is a leading failure mode in dental teeth. Virtually all chipping studies are limited to Vickers indentation on polished cusps of molar teeth. Such works are here extended to spherical contact. Occlusal loads are applied on the tooth\'s central fossa or a polished cusp using ball radii ranging from 0.4 to 5.16 mm. The chip dimensions are characterized by h/Dm and D/Dm, where h, D and Dm denote indent distance, chip size and tooth crown diameter. For the fossa loading, h/Dm, D/Dm and the least chipping force Pch are virtually independent of ball radius r for r < ≈ 4 mm. In this range, h/Dm and D/Dm lie between ≈0.30 to 0.36 and 0.51 to 0.69, respectively, while Pch equals ≈1330 N. For r > ≈ 4 mm, the failure occurs by debonding of enamel sectors from the dentin core. In the case of cusp loading, h/Dm < ≈ 0.3 while D/Dm and Pch vary with r. For relatively small h or large r, the failure occurs as soon as radial cracks initiate under the loading point. For a load applied near a cusp tip, the failure occurs by enamel debonding. Finally, the present work is easily extendable to fossil teeth of hominins and apes as well as prosthetic teeth. The morphological features obtained in such studies should provide quantitative means to assess the relationships between chip dimensions, chipping force and diet characteristics.
摘要：
边缘碎裂是牙科牙齿中的主要故障模式。实际上，所有切屑研究都仅限于磨牙的抛光尖齿上的维氏压痕。这样的工作在这里扩展到球形接触。使用半径范围为0.4至5.16mm的球在牙齿的中央窝或抛光的尖端上施加咬合负荷。芯片尺寸以h/Dm和D/Dm为特征，其中h,D和Dm表示缩进距离，芯片尺寸和牙冠直径。为了窝装载，h/Dm,对于r<≈4mm,D/Dm和最小碎裂力Pch实际上与球半径r无关。在这个范围内,h/Dm和D/Dm分别在0.30至0.36和0.51至0.69之间，而Pch等于约1330N。对于r>约4mm，失败是由于牙本质核心上的牙釉质部分脱粘而发生的。在尖点加载的情况下，h/Dm<≈0.3，而D/Dm和Pch随r变化。对于相对较小的h或较大的r，一旦在加载点下出现径向裂纹，就会发生故障。对于施加在尖端附近的负载，失效是由搪瓷脱粘引起的。最后,目前的工作很容易扩展到人类和猿类的化石牙齿以及假牙。在此类研究中获得的形态学特征应提供定量手段来评估芯片尺寸之间的关系，削片力和饮食特点。
