Department of Prosthetic Dentistry, University Hospital, LMU Munich, Goethestrasse 70, 80336, Munich, Germany.
Department of Conservative Dentistry and Periodontology, University Hospital, LMU Munich, Goethestrasse 70, 80336, Munich, Germany.
Clin Oral Investig. 2023 Jul;27(7):4007-4016. doi: 10.1007/s00784-023-05027-w. Epub 2023 Apr 22.
A variety of dental materials are available for the fabrication of telescopic crowns. The aim was to investigate the impact of material combinations and removal and insertion cycles on their retention forces.
CAD/CAM-fabricated cobalt-chromium-molybdenum (CoCr) and zirconia (ZrO) primary crowns were combined with polyetheretherketone (PEEK), polyetherketoneketone (PEKK), CoCr, and ZrO secondary crowns (four combinations included PEEK/PEKK secondary crowns in a thickness of 0.5 mm bonded to the CoCr tertiary construction), resulting in 12 different material combinations: CoCr-PEEK; CoCr-PEKK; CoCr-ZrO; CoCr-CoCr; CoCr-PEEK 0.5; CoCr-PEKK 0.5; ZrO-PEEK; ZrO-PEKK; ZrO-ZrO, ZrO-CoCr; ZrO-PEEK 0.5; and ZrO-PEKK 0.5 (n = 15 pairings per material combination). Pull-off tests were performed with a universal testing machine initially and after 500, 5000, and 10,000 removal and insertion cycles in a mastication simulator. Descriptive statistics with the Kolmogorov-Smirnov, Kruskal-Wallis, and Mann-Whitney U tests were computed (α = 0.05).
The tested parameters, material combination, and removal and insertion cycles had significant impact on the retention force values (p < 0.001). An increase in removal and insertion cycles was associated with a decrease in retention forces within CoCr and ZrO secondary crowns, regardless of the primary crown material. In contrast, PEEK and PEKK secondary crowns presented higher retention load values after 10,000 cycles than initially.
Different material combinations behaved differently after simulated removal and insertion regimens. This difference should be considered during treatment planning.
Telescopic crown systems should be made of materials with predictable retention forces that do not deteriorate with time. The implementation of new materials and technologies facilitates reproducibility and time-saving fabrication.
有多种牙科材料可用于制作伸缩式冠。本研究旨在探讨材料组合和去除-插入循环次数对其固位力的影响。
CAD/CAM 制作的钴铬钼（CoCr）和氧化锆（ZrO）初级冠与聚醚醚酮（PEEK）、聚醚酮酮（PEKK）、CoCr 和 ZrO 次级冠相结合（包括厚度为 0.5 毫米的 PEEK/PEKK 次级冠粘合到 CoCr 三级结构），共形成 12 种不同的材料组合：CoCr-PEEK、CoCr-PEKK、CoCr-ZrO、CoCr-CoCr、CoCr-PEEK 0.5、CoCr-PEKK 0.5、ZrO-PEEK、ZrO-PEKK、ZrO-ZrO、ZrO-CoCr、ZrO-PEEK 0.5 和 ZrO-PEKK 0.5（每种材料组合各有 15 对配对）。初始和经过 500、5000 和 10000 次去除-插入循环后，在咀嚼模拟器中使用万能试验机进行拔出试验。采用描述性统计、Kolmogorov-Smirnov、Kruskal-Wallis 和 Mann-Whitney U 检验进行计算（α=0.05）。
测试参数、材料组合和去除-插入循环次数对固位力值有显著影响（p＜0.001）。无论初级冠材料如何，去除-插入循环次数的增加与 CoCr 和 ZrO 次级冠固位力的降低有关。相比之下，PEEK 和 PEKK 次级冠在经过 10000 次循环后，其保持负载值高于初始值。
不同的材料组合在模拟去除-插入方案后表现不同。在治疗计划中应考虑这种差异。
伸缩式冠系统应使用具有可预测固位力且不会随时间恶化的材料制成。新材料和技术的应用有助于提高重复性和节约制造时间。
