Arnold Christin, Schweyen Ramona, Boeckler Arne, Hey Jeremias
Department of Prosthodontics, Martin-Luther-University Halle-Wittenberg, Magdeburger Str. 16, 06112 Halle, Germany.
Materials (Basel). 2020 Jul 20;13(14):3228. doi: 10.3390/ma13143228.
The aim of this study was to compare the retention forces after artificial aging of telescopic crowns fabricated either by a conventional lost-wax technique or by computer-aided design/computer-aided manufacturing (CAD-CAM) technology. Two types of telescopic crowns (0°) were fabricated conventionally using high-noble (group A) and non-precious metal (group B). CAD-CAM fabricated telescopic crowns (0°) were made of non-precious metal (group C). Retention forces were assessed before and after artificial aging and after axial and non-axial loading. Initially [I.] and after artificial aging [IV.], specimens of group C (I. 16.2 N; IV. 13.6 N) exhibited the highest retention forces. The retention forces in groups B (I. 12.5 N; IV. 4.6 N) and A (I. 9.6 N; IV. 2.9 N) were found to be lower than those of group C. The retention force differences between the groups were statistically significant ( < 0.001) at all measurement times [I. vs. IV.]. Different fabricated telescopic crowns with approximately identical designs and materials exhibited different retention forces and different long-term retentive behavior. An optimized CAD-CAM process with individually defined design parameters ensured telescopic crowns with a better fit. These findings might influence prospective clinical decision-making.
本研究的目的是比较采用传统失蜡法或计算机辅助设计/计算机辅助制造（CAD-CAM）技术制作的套筒冠在人工老化后的固位力。使用高贵金属（A组）和非贵金属（B组）通过传统方法制作了两种类型的套筒冠（0°）。采用CAD-CAM技术制作的套筒冠（0°）由非贵金属制成（C组）。在人工老化前后以及轴向和非轴向加载后评估固位力。最初[I.]和人工老化后[IV.]，C组样本（I. 16.2 N；IV. 13.6 N）表现出最高的固位力。发现B组（I. 12.5 N；IV. 4.6 N）和A组（I. 9.6 N；IV. 2.9 N）的固位力低于C组。在所有测量时间点[I.与IV.]，各组之间的固位力差异具有统计学意义（<0.001）。具有大致相同设计和材料的不同制作方法的套筒冠表现出不同的固位力和不同的长期固位行为。具有单独定义设计参数的优化CAD-CAM工艺可确保套筒冠具有更好的贴合度。这些发现可能会影响未来的临床决策。
