Statement of problem

Nonthermal argon plasma (NTAP) has been reported to improve the bond strength of resin cements to yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) ceramics. However, the effect of the inevitable delay before cementation and after treating Y-TZP ceramics with NTAP is unclear.

Purpose

The purpose of this in vitro study was to investigate whether delays of 8, 12, and 24 hours between the Y-TZP ceramic treatment with NTAP and the cementation would affect the surface energy and the bond strength of a self-adhesive resin cement to Y-TZP ceramic.

Material and methods

Sixty plates and 50 blocks of 3Y-TZP ceramic were divided into 2 groups (n=30 and n=25): as-sintered (AS) and airborne-particle abraded with 50-μm Al₂O₃ (APA). These groups were further divided into 5 subgroups (n=6 and n=5) according to the delay between the NTAP treatment and the measurement of surface energy and microtensile bond strength (μTBS) evaluation: (0, 8, 12, and 24 hours). For both 3Y-TZP surface conditions (AS and APA), a control group without NTAP treatment was used (ASC and APAC). The surface energy (SE) was evaluated with a goniometer and the 3Y-TZP elemental composition with X-ray photoelectron spectroscopy (XPS). For the μTBS test, the 3Y-TZP ceramic blocks were cemented to composite resin blocks with a self-adhesive resin cement. After storage in distilled water at 37 °C for 24 hours, the 3Y-TZP-composite resin blocks were sectioned into beams and submitted to a μTBS test. Data were submitted to 2-way ANOVA and the Tukey HSD test (α=.05).

Results

For the AS group, NTAP increased the SE irrespective of the delay before measurement: ASC<0 hour=8 hours=12 hours=24 hours (P<.05). For the APA group, except after 12 hours, NTAP also increased the surface energy (P<.05). XPS analysis showed an increase in the oxygen/carbon ratio after NTAP treatment for both groups. For the AS group, NTAP increased the μTBS after 0, 8, and 12 hours (P<.05), whereas for the APA group this occurred only after 8 hours (P<.05). For the AS and APA groups, the highest μTBS was reached after 8 hours (P<.05).

Conclusions

Treatment of 3Y-TZP ceramic with NTAP improved the SE and increased the μTBS of self-adhesive resin cement to 3Y-TZP ceramic. These effects were time dependent, with better results at 8 hours after NTAP treatment.

中文翻译：

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胶凝延迟对非热氩等离子体处理的自粘树脂胶黏剂与氧化钇稳定的四方氧化锆多晶陶瓷粘接的影响

问题陈述

据报道，非热氩等离子体（NTAP）可以改善树脂水泥与氧化钇稳定的四方氧化锆多晶（Y-TZP）陶瓷的结合强度。但是，在胶结之前和用NTAP处理Y-TZP陶瓷后不可避免的延迟的影响尚不清楚。

目的

这项体外研究的目的是研究用NTAP进行Y-TZP陶瓷处理与胶结之间的8、12和24小时的延迟是否会影响自粘树脂胶粘剂与Y的表面能和粘结强度-TZP陶瓷。

材料与方法

将60块板和50个3Y-TZP陶瓷块分为2组（n = 30和n = 25）：烧结（AS）和用50μmAl ₂ O ₃磨蚀的气载颗粒（APA）。根据NTAP处理与测量表面能和微拉伸结合强度（μTBS）之间的延迟，将这些组进一步分为5个子组（n = 6和n = 5）：（0、8、12和24小时）。对于3Y-TZP表面条件（AS和APA），均使用未经NTAP处理的对照组（ASC和APAC）。用测角计评估表面能（SE），并用X射线光电子能谱法（XPS）评估3Y-TZP元素组成。对于μTBS测试，将3Y-TZP陶瓷块用自粘树脂胶粘剂粘结到复合树脂块上。在37°C的蒸馏水中储存24小时后，将3Y-TZP复合树脂块切成束，并进行μTBS测试。将数据提交给2通ANOVA和Tukey HSD测试（α= .05）。

结果

对于AS组，无论测量前的延迟如何，NTAP都会增加SE：ASC <0小时= 8小时= 12小时= 24小时（P <.05）。对于APA组，除了12小时后，NTAP还增加了表面能（P <.05）。XPS分析显示，两组在NTAP处理后，氧/碳比均增加。对于AS组，NTAP在0、8和12小时后增加μTBS（P <.05），而对于APA组，仅在8小时后才发生（P <.05）。对于AS和APA组，在8小时后达到了最高的μTBS（P <.05）。

结论

用NTAP处理3Y-TZP陶瓷改善了SE，并增加了自粘性树脂水泥与3Y-TZP陶瓷的μTBS。这些影响是时间依赖性的，在NTAP治疗后8小时效果更好。