Purpose

Lithium disilicate glass-ceramics (LS2 GC) are widely used as dental prosthetics and dental restorations. Based LS2 GC have hardness and translucency similar to that of natural teeth. This study aims to investigate the tribological features of LS2 GC with crystalline volume fraction of 64% and different crystal sizes from 8 µm to 34 µm for different counterparts.

Design/methodology/approach

The tribological behavior was investigated using a pin-on-disc tribometer with alumina and tungsten carbide (WC) spheres, applied load of 5 N and sliding speed of 5 cm/s at normal conditions. The coefficient of friction was measured continuously up to 10,000 sliding cycles. The specific wear rate was calculated from tribological and profile measurements. The wear mechanism was investigated by surface morphology analysis.

Findings

The coefficient of friction during running-in varied from 0.8 to 1.0 for the alumina counterpart, because of severe wear. Afterwards, it reduced and reached a stationary regime, characterized by a mild wear regime and the formation of a tribolayer formed by the debris. For the WC counterpart, the coefficient of friction curves increased initially with sliding cycles up to a stationary regime. The samples tested against WC presented the lowest specific wear rate (k), and no variation of wear rate with crystal size was observed. For samples tested against the alumina, crystallization and crystal size increased the wear resistance.

Originality/value

This study evaluated the effect of different counterfaces on the tribological properties of the LS2 GC, an important glass-ceramic base for many dental prosthetics and dental restorations, discussing results in light of the contact mechanics. Different specific wear rates, wear regimes and dependence on the glass-ceramic microstructure were observed depending on the counterpart.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2019-0352/

中文翻译：

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晶体尺寸对二硅酸锂玻璃陶瓷在氧化铝和碳化钨球上滑动的摩擦学性能的影响

目的

二硅酸锂玻璃陶瓷（LS2 GC）被广泛用作义齿和修复牙齿。基于LS2的GC具有与天然牙齿相似的硬度和半透明性。这项研究的目的是研究LS2 GC的摩擦学特性，该晶体体积分数为64％，并且晶体大小从8 µm到34 µm不等。

设计/方法/方法

使用带氧化铝和碳化钨（WC）球的针盘式摩擦计，在正常条件下施加5 N的载荷和5 cm / s的滑动速度，研究了摩擦学行为。连续测量摩擦系数直至10,000个滑动循环。根据摩擦学和轮廓测量来计算比磨损率。通过表面形态分析研究了磨损机理。

发现

对于氧化铝配套件，由于严重磨损，磨合期间的摩擦系数在0.8到1.0之间变化。之后，它减少并达到了稳定状态，其特征是轻微的磨损状态和由碎屑形成的摩擦层的形成。对于WC对应物，摩擦系数曲线最初随着滑动循环而增加，直至达到稳定状态。针对WC进行测试的样品呈现出最低的比磨损率（k），并且未观察到磨损率随晶体尺寸的变化。对于经氧化铝测试的样品，结晶和晶体尺寸增加了耐磨性。

创意/价值

这项研究评估了不同表面对LS2 GC的摩擦学性能的影响，LS2 GC是许多牙科修复和牙科修复的重要玻璃陶瓷基础，并根据接触机理讨论了结果。观察到不同的比磨损率，磨损方式以及对玻璃陶瓷微结构的依赖性。

同行评审

本文的同行评审历史记录可在以下网址获得：https://publons.com/publon/10.1108/ILT-08-2019-0352/