Oral Technology, Dental School, University of Bonn, Welschnonnenstr. 17, 53111, Bonn, Germany.
Department of Prosthetic Dentistry, Preclinical Education and Materials Science, Dental School, Rheinische Friedrich-Wilhelms University, University of Bonn, Welschnonnenstr. 17, 53111, Bonn, Germany.
Clin Oral Investig. 2021 Aug;25(8):4895-4905. doi: 10.1007/s00784-021-03797-9. Epub 2021 Jan 28.
The aim of this study was, firstly, to analyse the long-time fatigue behaviour of crowns constructed from a novel polyetherketoneketone (PEKK) polymer, using artificial prepared teeth. Secondly, to determine the effect of the material's stiffness that used as an artificial prepared tooth on the fatigue life of the PEKK crowns in comparison to human prepared teeth.
Veneered crowns with a PEKK framework were constructed on three different prepared teeth: artificial polymethyl methacrylate (PMMA) teeth, artificial CoCr teeth and extracted human teeth. As far as applicable, the loading protocol was based on EN ISO 14801:2007 for fatigue testing of dental implants. After initial static fracture tests on three specimens from each group, the remaining crowns were loaded with different force levels until fracture or until 2 × 10 loading cycles were reached. The number of loading cycles until failure was recorded. Wöhler curves were created to display the fatigue limits.
Static fracture limits as well as fatigue limits differed for all three core materials. The static fracture tests resulted in fracture limits of 1200 (± 293) N for the PMMA group, 1330 (± 219) N for the CoCr group and 899 (± 96) N for the human tooth group. Fatigue limits of 770 N, 840 N and 720 N were determined for the PMMA group, CoCr group and human tooth group, respectively.
The determined fatigue limit of above 720 N (depending on the core material) is sufficiently high and a good performance of this crown material is expected in the clinical loading life. The results showed that using artificial teeth instead of natural teeth for fatigue testing of crowns might result in an overestimation of the fatigue limits of the crown material.
PEKK-made crowns offer a stable and priceworthy treatment for patients, in particular those that suffer from metal allergy.
本研究的目的首先是使用人工制备的牙齿分析新型聚醚酮酮（PEKK）聚合物制成的牙冠的长期疲劳行为。其次，确定用作人工制备牙的材料的刚度对 PEKK 牙冠疲劳寿命的影响，与人类制备牙相比。
在三种不同制备的牙齿上构建了具有 PEKK 框架的贴面冠：人工聚甲基丙烯酸甲酯（PMMA）牙齿、人工 CoCr 牙齿和提取的人牙齿。在可行的情况下，加载方案基于 EN ISO 14801：2007 中用于牙种植体疲劳测试的标准。在对每组三个样本进行初始静态断裂测试后，用不同的力水平加载其余牙冠，直到断裂或达到 2×10 个加载循环。记录失效的加载循环数。创建沃勒曲线以显示疲劳极限。
所有三种核心材料的静态断裂极限和疲劳极限都有所不同。静态断裂测试导致 PMMA 组的断裂极限为 1200（±293）N，CoCr 组为 1330（±219）N，人牙组为 899（±96）N。PMMA 组、CoCr 组和人牙组的疲劳极限分别确定为 770 N、840 N 和 720 N。
确定的疲劳极限高于 720 N（取决于核心材料）足够高，预计这种牙冠材料在临床负荷寿命中具有良好的性能。结果表明，使用人工牙齿代替天然牙齿进行牙冠疲劳测试可能会导致牙冠材料疲劳极限的高估。
PEKK 制成的牙冠为患者提供了一种稳定且价格合理的治疗方法，特别是那些患有金属过敏的患者。
