State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Prosthodontics, School of Stomatology, Fourth Military Medical University, Xi'an, 710032, China.
State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China.
J Dent. 2019 Nov;90:103210. doi: 10.1016/j.jdent.2019.103210. Epub 2019 Oct 7.
The present study examined the effects of Na→K ion-exchange on the wear performance of feldspathic veneering porcelain.
Bar and disk specimens were prepared using IPS classic as the feldspathic veneering porcelain. After ion-exchange by immersion of the specimens in melted KNO at two temperatures for different time-periods, the bars were tested for flexural strength and Vickers surface hardness. The disks were paired with zirconia antagonists and tested with a pin-on-disk tribometer with 10 N for 70☓10 wear cycles in artificial saliva. Wear analysis of the porcelain and zirconia was performed using 3D profilometer and analysed with one-way analysis of variance and Tukey's post-hoc pairwise comparison procedures. Worn surfaces were examined with scanning electron microscopy.
The feldspathic veneering porcelain exhibited strong time-dependent wear behaviour, with typical running-in and steady wear stages. Ion-exchange treatments at 380 °C and 440 °C both enhanced the mechanical properties, decreased the wear rates of running-in wear and steady wear. The wear performance of porcelain treated by ion-exchange at lower temperature (380 °C) was improved significantly, especially reducing the wear rate of the running-in stage.
A thicker ion-exchange layer with less stress relaxation may be obtained by ion-exchange at lower exchange temperature for a long processing time. Such a protocol improves the wear performance of the porcelain effectively.
Restorations with veneering porcelain may fail prematurely due to excessive wear. It important to improve the wear performance of the porcelain. Ion-exchange has the potential to strengthen dental veneering porcelain. Understanding the effect of ion-exchange on the wear performance of porcelain provides insight improving the wear performance of these restorations.
本研究探讨了 Na→K 离子交换对长石质饰面瓷磨损性能的影响。
采用 IPS classic 作为长石质饰面瓷，制备棒和盘试件。将试件浸入熔融 KNO 中进行离子交换，在两种温度下不同时间后，测试棒的抗弯强度和维氏表面硬度。将圆盘与氧化锆对磨件配对，在人工唾液中以 10N 的载荷进行 70☓10 个磨损循环的销盘式摩擦磨损试验。采用 3D 轮廓仪对瓷和氧化锆的磨损进行分析，并采用单因素方差分析和 Tukey 事后两两比较程序进行分析。用扫描电子显微镜观察磨损表面。
长石质饰面瓷表现出强烈的时间依赖性磨损行为，具有典型的磨合和稳定磨损阶段。在 380°C 和 440°C 下进行离子交换处理均提高了力学性能，降低了磨合磨损和稳定磨损的磨损率。在较低温度（380°C）下进行离子交换处理的瓷的磨损性能得到显著改善，特别是降低了磨合阶段的磨损率。
较长时间的低温（380°C）离子交换可以获得具有较少应力松弛的较厚的离子交换层，从而有效提高瓷的磨损性能。
由于过度磨损，覆层瓷修复体可能会提前失效。改善瓷的磨损性能非常重要。离子交换具有增强牙科饰面瓷的潜力。了解离子交换对瓷磨损性能的影响有助于改善这些修复体的磨损性能。
