The purpose of this in vitro study was to evaluate the influence of mechanical load cycling (MLC), which simulated mastication, alone or combined with thermal cycling (TC), on the resin shear bond strength (SBS) to zirconia. Two resin cements (Panavia F2.0 and RelyX U200) were bonded (bonding area: 2.38 mm) to air-abraded zirconia (Everest ZS-Ronde). The specimens were subjected to SBS test before and after TC (5000 cycles), MLC (5000 cycles in 37 °C water), TC/MLC, or MLC/TC aging (n = 15). Before SBS test, the mechanical and physical properties of the two resin cements were studied (n = 5). For both resins, unlike TC (p > 0.05), the three MLC-containing aging conditions significantly decreased the SBS values when compared to the non-aged condition (p < 0.05). In the case of MLC-only aging, RelyX U200, with significantly higher hydrophobicity (p = 0.004), showed a significantly higher SBS value than Panavia F2.0 (p = 0.035). The MLC aging-containing groups showed increased occurrence of mixed failure. The application of MLC combined with TC may more closely simulate intraoral conditions.

中文翻译：

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通过热循环或机械负载循环或它们的组合挑战树脂-氧化锆界面

这项体外研究的目的是评估机械负载循环（MLC）单独或与热循环（TC）一起模拟咀嚼时对氧化锆树脂剪切强度（SBS）的影响。将两种树脂水泥（Panavia F2.0和RelyX U200）粘合（粘合面积：2.38 mm）到空气研磨的氧化锆（Everest ZS-Ronde）。在TC（5000个循环），MLC（在37°C的水中5000个循环），TC / MLC或MLC / TC老化（n = 15）之前和之后，对样品进行SBS测试。在进行SBS试验之前，研究了两种树脂水泥的机械​​和物理性能（n = 5）。对于两种树脂，不像TC（p> 0.05），与未老化条件相比，三种含有MLC的老化条件显着降低了SBS值（p＜0.05）。在仅MLC老化的情况下，具有显着更高的疏水性（p = 0.004）的RelyX U200显示的SBS值比Panavia F2.0（p = 0.035）高得多。包含MLC老化的基团显示混合失效的发生率增加。MLC与TC结合使用可能会更紧密地模拟口腔条件。