Department of Prosthodontics and Dental Materials, Medical Faculty, RWTH Aachen University, Aachen, Germany.
Private Office, Eckernförde, Germany.
J Prosthodont Res. 2019 Jul;63(3):347-353. doi: 10.1016/j.jpor.2018.10.010. Epub 2019 Mar 14.
To investigate the impact of inlay design and number of retainer wings on the failure load of all-ceramic resin-bonded inlay-retained cantilever fixed dental prostheses (IRCFDPs) made from a computer-aided design/computer-aided manufacturing (CAD/CAM) yttrium-oxide partially-stabilized zirconia framework(Y-TZP).
Sixty-four extracted human first molars were divided according to preparation design into four groups. Teeth were provided with IRCFDPs representing a premolar pontic and a retainer of variable design: (R1S) shallow inlay/one lingual retainer wing, (R2S) shallow inlay/two retainer wings (lingual/buccal), (R1D) deep inlay/one lingual retainer wing and (R2D) deep inlay/two retainer wings (lingual/buccal). All IRCFDPs were cemented using adhesive resin. Quasi-static fracture strength (QSFS) was tested for 32 specimens after 3 days in a universal testing machine (UTM). The other specimens were stored in a water bath (150 days/37 °C) and thermocycled (37,500 times, 5-55 °C); then exposed to dynamic loading in a chewing simulator (50 N/1,200,000 cycles).
The median QSFS (N) for the different designs were: R1S:105.1, R1D:167.5, R2S:147.9, R2D:232.3. The number of retainer wings had a statistically significant influence on the fracture load of both groups, whereas the inlay design had an impact only in the double-retainer wing group. Under dynamic loading, lower failure loads within all groups were reported except for the group R2S. The number of retainer wings continued to significantly influence the failure loads of both groups, whereas no influence of inlay design could be revealed.
Double-retainer IRCFDPs showed promising results for replacing single premolars. The inlay design seems to have no significant influence on the fracture strength of these restorations.
研究嵌体设计和固位翼数量对计算机辅助设计/计算机辅助制造（CAD/CAM）氧化钇部分稳定氧化锆框架（Y-TZP）制作的全瓷树脂粘结嵌体保留的悬臂固定义齿（IRCFDP）的失效负荷的影响。
根据预备设计，将 64 个人工第一磨牙分为四组。为 IRCFDP 提供了可变设计的前磨牙桥体和固位体：（R1S）浅嵌体/一个舌侧固位翼，（R2S）浅嵌体/两个固位翼（舌侧/颊侧），（R1D）深嵌体/一个舌侧固位翼和（R2D）深嵌体/两个固位翼（舌侧/颊侧）。所有 IRCFDP 均使用粘结树脂粘结。在万能试验机（UTM）中测试 32 个样本 3 天后进行准静态断裂强度（QSFS）测试。其余样本在水浴（150 天/37°C）中储存并进行热循环（37,500 次，5-55°C）；然后在咀嚼模拟器中进行动态加载（50N/1,200,000 次循环）。
不同设计的 QSFS（N）中位数分别为：R1S：105.1，R1D：167.5，R2S：147.9，R2D：232.3。固位翼数量对两组的断裂负荷均有统计学显著影响，而嵌体设计仅对双固位翼组有影响。在动态加载下，除 R2S 组外，所有组的失效负荷均较低。固位翼数量继续对两组的失效负荷有显著影响，而嵌体设计没有影响。
双固位 IRCFDP 有望替代单个前磨牙。嵌体设计似乎对这些修复体的断裂强度没有显著影响。
