Objective

To investigate the impact of high-speed sintering, layer thickness and artificial aging in a chewing simulator on the fracture load (FL) and two-body wear (2BW) of 4Y-TZP crowns.

Methods

4Y-TZP crowns (Ceramill Zolid HT+, Amann Girrbach AG) in three different layer thicknesses (0.5, 1.0, 1.5; N = 192, n = 64/group) were manufactured using CAD/CAM technology and sintered at 1580 °C (high-speed sintering) or 1450 °C (control group). Specimens were polished in two-steps and bonded to standardized CoCr abutments with Multilink Automix (Ivoclar Vivadent). 2BW after 6000 thermo- and 1,200,000 chewing-cycles employing enamel antagonists was determined using best fit machining. FL was tested before and after artificial aging. Univariate ANOVAs, post hoc Scheffé, unpaired t-, Kruskal–Wallis- and Mann–Whitney-U-test were computed (p < 0.05).

Results

High-speed sintering resulted in less 2BW of the zirconia than the control group (p = 0.013). High-speed sintering (p = 0.001–0.006) and an increase in layer thickness (p < 0.001–0.012) resulted in higher FL values, while artificial aging led to a reduction of FL (p < 0.001).

Significance

As high-speed sintering resulted in less two-body wear of the zirconia and comparable or even higher fracture load results than the control group, this cost- and time efficient alternative presents promising mechanical results.

中文翻译：

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高速烧结，层厚和人工时效对氧化锆冠的断裂载荷和两体磨损的影响。

目的

为了研究高速烧结，层厚和咀嚼模拟器中的人工时效对4Y-TZP牙冠的断裂载荷（FL）和两体磨损（2BW）的影响。

方法

 使用CAD / CAM技术制造三种厚度（0.5、1.0、1.5; N  = 192，n = 64 /组）的4Y-TZP牙冠（Ceramill Zolid HT +，Amann Girrbach AG），并在1580°C（高）下烧结高速烧结）或1450°C（对照组）。样品经过两步抛光，并通过Multilink Automix（Ivoclar Vivadent）粘结到标准的CoCr基台上。使用最佳拟合加工，测定了使用搪瓷拮抗剂的6000次热循环和1,200,000次咀嚼循环后的2BW。FL在人工老化之前和之后进行了测试。计算单变量方差分析，事后谢菲，不成对t-，Kruskal-Wallis-和Mann-Whitney- U-检验（p  <0.05）。

结果

高速烧结导致氧化锆的2BW比对照组少（p  = 0.013）。高速烧结（p  = 0.001–0.006）和层厚增加（p  <0.001–0.012）导致较高的FL值，而人工时效导致FL降低（p  <0.001）。

意义

由于高速烧结导致氧化锆的二体磨损更少，并且断裂载荷的结果比对照组要高，甚至更高，因此这种具有成本效益和时间效率的替代方案表现出令人鼓舞的机械效果。