Objective

To evaluate the effect of different pH media on zirconia-reinforced lithium silicate glass ceramic and how they interact with opposing dentition after being aged in different pH cycling and high temperature conditions.

Methods

Twenty-five rectangular shaped specimens were prepared from lithium silicate reinforced with zirconia blanks (Suprinity, Vita Zahnfabrick) and stored in different pH media (3 & 7.2) for different periods (24 h & 7 days) at temperature (55 °C). After their surface roughness (Ra) evaluation, aged ceramic specimens were subjected to cyclic abrasive wear with opposing natural teeth enamel for 150,000 cycles using a chewing simulator. Weight loss and Scanning Electron Microscope (SEM) images were used to evaluate the cyclic wear results.

Results

After different pH storage, ceramic group stored at 3 pH for 1-W (1 week) gave significantly higher mean Ra value (0.618 μm ± 0.117) than control lowest mean value (0.357 μm ± 0.054) before cyclic wear. On the other hand, it caused the least significant weight loss value (0.004 gm ± 0.001) to opposing tooth enamel. There was significant tooth enamel weight loss (0.043 gm ± 0.004) when opposed with ceramic group stored in 3 pH media for 24 h (24-H). Their SEM images showed a prominent wear scar on enamel cusp tip. There was a significant increase in surface roughness Ra of ceramic material after abrasive cyclic wear.

Significance

Great attention should be paid to Ra of this type of glass ceramic even if it is considered as minimal values. It can induce a significant amount of enamel tooth wear after a period equivalent to one year of intra-oral function rather than the significantly higher surface Ra of such ceramic type can do.

中文翻译：

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加速老化后与氧化锆增强的硅酸锂玻璃陶瓷相对的天然牙齿表面的体外磨损

客观的

为了评估不同pH介质对氧化锆增强的硅酸锂玻璃陶瓷的影响，以及它们在不同的pH循环和高温条件下老化后如何与相反的牙列相互作用。

方法

用氧化锆毛坯（Suprinity，Vita Zahnfabrick）增强的硅酸锂制备了二十五个矩形样品，并在温度（55°C）下在不同的pH介质（3＆7.2）中保存了不同的时间（24 h＆7天）。在评估其表面粗糙度（Ra）之后，使用咀嚼模拟器对老化的陶瓷样品和相对的天然牙齿瓷釉进行150000次循环磨损。失重和扫描电子显微镜（SEM）图像用于评估周期性磨损结果。

结果

在不同的pH值存储后，在3个pH值下存储1W（1周）的陶瓷组的平均Ra值（0.618μm±0.117）显着高于循环磨损前的对照组最低均值（0.357μm±0.054）。另一方面，它对相对的牙釉质造成的最小重量损失值（0.004 gm±0.001）最小。与在3种pH介质中存储24 h（24-H）的陶瓷组相反，牙釉质的重量损失显着（0.043 gm±0.004 ）。他们的SEM图像显示牙釉质尖头上有明显的磨损痕迹。磨料循环磨损后，陶瓷材料的表面粗糙度Ra显着增加。

意义

即使将这种类型的玻璃陶瓷的Ra视为最小值，也应格外注意。在相当于一年的口腔内功能的一段时间后，它会引起牙釉质的大量磨损，而不是这种陶瓷类型的明显更高的表面Ra。