Abstract Wear of enamel during tooth brushing is a complex phenomenon with many variables affecting the level of loss. Toothpastes contain angular abrasive particles at a concentration of 12%–15% v/v abrasive designed to remove biofilm and extrinsic stains that also have the potential to harm the tooth enamel resulting in wear. Toothpastes contain multi-modal particles in the size range of 4μm–12μm. The aim of this paper is to develop an understanding of the relationship between the combined effects of particle shape, size, size distribution and load on the volume loss of enamel under abrasive testing. Micro-abrasion testing using a Nylon ball, to simulate the toothbrush, was undertaken on hydrated bovine enamel disks using volume concentrations of 5% – 20% v/v alumina and silica. Post experimental surface analysis was performed to analyse the wear scar morphology and groove analysis. The synergistic effects were calculated of bimodal particles vs. mono sized particles. Mono-sized particles as compared to bimodal, appeared to give the best outcome and least wear of enamel. A positive synergy existed for the alumina and silica bimodal tests, indicating the bimodal particle distribution was causing more wear than the mono-sized particles. The mechanism of material removal was a combination of crushing and fracture of the enamel prisms (rods), followed by micro-chipping and removal of enamel. The magnitude and the distribution of the particle sizes is the most dominant factor in determining the levels of wear, with smaller particles and narrow distributions of the particle size reducing the magnitude of wear. The shape of the particles is also a major factor influencing wear, with the spherical tests generating lower wear rates than the angular tests.

中文翻译：

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磨粒形状和粒度分布对微磨蚀牙釉质体积损失的影响

摘要 刷牙过程中牙釉质的磨损是一个复杂的现象，其影响因素有很多。牙膏含有浓度为 12%–15% v/v 磨料的角磨粒，旨在去除生物膜和外源性污渍，这些污渍也有可能损害牙釉质，导致磨损。牙膏包含大小范围为 4μm-12μm 的多模态颗粒。本文的目的是了解颗粒形状、尺寸、尺寸分布和负载对磨料测试下牙釉质体积损失的综合影响之间的关系。使用尼龙球模拟牙刷的微磨损测试是在使用体积浓度为 5% – 20% v/v 氧化铝和二氧化硅的水合牛搪瓷盘上进行的。进行实验后表面分析以分析磨痕形态和凹槽分析。计算双峰颗粒与单尺寸颗粒的协同效应。与双峰相比，单一尺寸的颗粒似乎提供了最好的结果和最少的牙釉质磨损。氧化铝和二氧化硅双峰试验存在积极的协同作用，表明双峰颗粒分布比单尺寸颗粒造成更多磨损。材料去除的机制是釉质棱柱（棒）的压碎和断裂的组合，然后是微碎屑和釉质的去除。颗粒大小的大小和分布是决定磨损程度的最主要因素，较小的颗粒和较窄的颗粒大小分布会降低磨损的大小。