Zucuni Camila Pauleski, Pereira Gabriel Kalil Rocha, Valandro Luiz Felipe
Faculty of Odontology, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul, Brazil.
J Mech Behav Biomed Mater. 2020 Mar;103:103528. doi: 10.1016/j.jmbbm.2019.103528. Epub 2019 Nov 11.
This study aims to evaluate the effect of distinct surface treatments (grinding, polishing and glaze) of the occlusal surface of fully-stabilized zirconia (FSZ) simplified restorations bonded onto epoxy resin on the fatigue behavior of the restorations. Disc shaped specimens of FSZ (IPS e.max Zircad MT Multi) were produced (Ø = 10 mm and 0.8 mm in thickness) and randomly allocated into 5 groups, considering the factor 'surface treatment' of the occlusal surface: Ctrl - as-sintered; Gr - ground with coarse diamond bur; Gr + Pol- grinding + polishing with two-step polishing system; Gr + Gl - grinding + glaze application; Gr + Pol + Gl - grinding + polishing + glaze application. Next, the FSZ intaglio surface was air-abraded with 45 μm aluminum oxide powder for 10 s at 15 mm of distance under 2 bar pressure and the discs were adhesively cemented (Multilink Automix) onto its dentin analogue pair (Ø = 10 mm; thickness = 2.7 mm). Finally, the step-stress fatigue test was executed (load ranging from 200 to 1300 N; step-size of 100N; 10,000 cycles per step, 20 Hz). In addition, surface topography, roughness, phase transformation and fractography analyses were performed. Grinding altered the topographical pattern introducing defects into the material surface and increasing roughness. Polishing and glaze application led to a smoothening effect, reducing surface defects and statistically decreasing roughness. However, the effect on roughness of polishing and glaze was statistically similar. No phase transformation was observed, thus only cubic and tetragonal phases were detected. No surface treatment had a deleterious effect regarding the fatigue failure load, number of cycles for failure and survival rates. All failures (cracks) started on the bonding surface. Thus, polishing and glaze are indicated to reduce surface roughness, despite not leading to differences in terms of fatigue performance.
本研究旨在评估完全稳定氧化锆（FSZ）简化修复体咬合面的不同表面处理（打磨、抛光和上釉）对粘结在环氧树脂上的修复体疲劳行为的影响。制作了FSZ（义获嘉e.max Zircad MT Multi）圆盘形试件（直径 = 10毫米，厚度0.8毫米），并根据咬合面的“表面处理”因素随机分为5组：对照组 - 烧结态；Gr - 用粗金刚石车针打磨；Gr + Pol - 打磨 + 用两步抛光系统抛光；Gr + Gl - 打磨 + 上釉；Gr + Pol + Gl - 打磨 + 抛光 + 上釉。接下来，FSZ内表面用45μm氧化铝粉末在2巴压力下于15毫米距离处进行10秒的空气喷砂处理，然后将圆盘用粘结剂（Multilink Automix）粘结到其牙本质类似物对上（直径 = 10毫米；厚度 = 2.7毫米）。最后，进行阶梯应力疲劳试验（载荷范围为200至1300牛；步长为100牛；每步10,000次循环，20赫兹）。此外，还进行了表面形貌、粗糙度、相变和断口分析。打磨改变了形貌模式，在材料表面引入缺陷并增加粗糙度。抛光和上釉产生了平滑效果，减少了表面缺陷并在统计学上降低了粗糙度。然而，抛光和上釉对粗糙度的影响在统计学上相似。未观察到相变，因此仅检测到立方相和四方相。对于疲劳失效载荷、失效循环次数和生存率，没有表面处理产生有害影响。所有失效（裂纹）均始于粘结面。因此，尽管抛光和上釉在疲劳性能方面未导致差异，但仍建议用于降低表面粗糙度。
