Doctoral student, Post-Graduate Program in Dentistry, Dental School, University of Passo Fundo (UPF), Rio Grande do Sul, Brazil.
Professor of Dental Materials, Post-Graduate Program in Dentistry, Dental School, University of Passo Fundo (UPF), Rio Grande do Sul, Brazil.
J Prosthet Dent. 2019 Jun;121(6):929-934. doi: 10.1016/j.prosdent.2018.08.008. Epub 2019 Feb 10.
Restorative materials are cemented on different types of substrates, such as dentin, metal, and glass-fiber posts with composite resin cores.
The purpose of this in vitro study was to evaluate the failure behavior after cycling fatigue of a polymer-infiltrated ceramic network material (PICN; VITA ENAMIC) cemented on different supporting substrates.
PICN plates (N=80) were obtained from computer-assisted design and computer-assisted manufacturing (CAD-CAM) blocks and cemented with a resin cement to 4 different supporting substrates (n=20): (1) human dentin (PICNDen); (2) dentin analog (PICNDenAn); (3) nickel-chromium alloy (PICNNiCr); and (4) composite resin plus fiberglass post (PICNRc). For comparison, the fracture behavior of a feldspathic ceramic (FelDenAn; VITABLOCS Mark II) and an indirect composite resin (ResDenAn; Opallis LAB Resin) cemented to the DenAn substrate was investigated (n=20). Thus, specimens were composed of the restorative material layer (1-mm thick) resin cemented (0.1-mm-thick layer) to a 2-mm-thick supporting substrate. All specimens were subjected to mechanical cycling (MC) using a pneumatic cycling machine (500 000 cycles, 2 Hz, 50 N). Specimens that did not fracture during cycling were tested under compression using a universal testing machine at a cross-head speed of 0.5 mm/min until the sound of the first crack was detected using an acoustic system. Failure data were statistically evaluated using Weibull distribution. Failures were classified as radial crack, cone crack, combined, and catastrophic fracture.
All FelDenAn specimens were fractured during MC. Only 4 PICNRc specimens survived MC, so their fracture load data were not statistically analyzed. PICNNiCr showed the greatest characteristic load (L) value, followed by ResDenAn. Groups PICNDenAn and PICNDen showed lower and similar L but statistically different Weibull modulus (m). There was a significant relationship between experimental group and failure mode (P<.001). FelDenAn and PICNRc had a higher frequency of radial cracks, whereas PICNNiCr failed from cone cracking.
The supporting substrate influenced the failure behavior of PICN. When the substrate had a higher elastic modulus than the restorative material, better mechanical behavior was observed.
修复材料被粘接到不同类型的基底上，例如牙本质、金属和玻璃纤维桩以及复合树脂核。
本体外研究的目的是评估循环疲劳后聚合物渗透陶瓷网络材料（PICN；VITA ENAMIC）粘接到不同支撑基底上的失效行为。
从计算机辅助设计和计算机辅助制造（CAD-CAM）块中获得 PICN 板（N=80），并用树脂水泥粘接到 4 种不同的支撑基底上（n=20）：（1）人牙本质（PICNDen）；（2）牙本质模拟物（PICNDenAn）；（3）镍铬合金（PICNNiCr）；和（4）复合树脂加玻璃纤维桩（PICNRc）。为了进行比较，还研究了粘接到 DenAn 基底上的长石陶瓷（FelDenAn；VITABLOCS Mark II）和间接复合树脂（ResDenAn；Opallis LAB Resin）的断裂行为（n=20）。因此，试件由修复材料层（1 毫米厚）和粘接到 2 毫米厚支撑基底上的树脂水泥层（0.1 毫米厚）组成。所有试件均使用气动循环机进行机械循环（MC）（500000 次循环，2 Hz，50 N）。在循环过程中未断裂的试件在万能试验机上以 0.5 毫米/分钟的十字头速度进行压缩测试，直到使用声学系统检测到第一个裂纹的声音。使用威布尔分布对失效数据进行统计学评估。失效分类为径向裂纹、锥形裂纹、组合和灾难性断裂。
所有 FelDenAn 试件在 MC 过程中均断裂。只有 4 个 PICNRc 试件在 MC 后幸存下来，因此未对其断裂载荷数据进行统计学分析。PICNNiCr 显示出最大特征载荷（L）值，其次是 ResDenAn。PICNDenAn 和 PICNDen 组显示出较低且相似的 L，但威布尔模数（m）统计学上有差异。实验组与失效模式之间存在显著关系（P<.001）。FelDenAn 和 PICNRc 的径向裂纹频率较高，而 PICNNiCr 则从锥形裂纹处失效。
支撑基底影响 PICN 的失效行为。当基底的弹性模量高于修复材料时，观察到更好的机械性能。
