Lassila Lippo, Mangoush Enas, Vallittu Pekka K, Garoushi Sufyan
Department of Biomaterials Science and Turku Clinical Biomaterials Centre -TCBC Institute of Dentistry, University of Turku, Turku, Finland.
City of Turku Welfare Division, Oral Health Care, Turku, Finland.
J Prosthodont Res. 2023 Apr 12;67(2):271-277. doi: 10.2186/jpr.JPR_D_22_00050. Epub 2022 Jul 28.
To evaluate the fracture behavior of inlay-retained fixed partial dentures (IRFPDs) made of experimental short fiber-reinforced composite (SFRC) computer-aided design/computer-aided manufacturing (CAD/CAM) block before and after cyclic fatigue aging.
Five groups (n=20/group) of three-unit posterior IRFPDs were fabricated. The first and second groups were CAD/CAM fabricated from experimental SFRC blocks or lithium-disilicate (IPS e.max CAD, IVOCLAR) materials, the third group comprised a three-dimensional-printed composite (Temp PRINT, GC), and the fourth and fifth groups comprised conventional laboratory flowable composite (Gradia Plus, GC) and commercial flowable SFRC (everX Flow, GC), respectively. All IRFPDs were luted into a metal jig with adhesive dual-cure resin cement (RelyX Ultimate, 3M ESPE). Half the IRFPDs per group (n=10) were subjected to fatigue aging for 10,000 cycles. The remaining half were statically loaded until fracture without fatigue aging. The load was applied vertically between triangular ridges of the buccal and lingual cusps. The fracture mode was visually examined using optical and scanning electron microscopy (SEM). Data were statistically analyzed using a two-way analysis of variance (ANOVA) followed by Tukey's HSD test.
ANOVA revealed that IRFPDs made of experimental SFRC CAD/CAM had the highest (P<0.05) load-bearing capacity before (2624±463 N) and after (2775±297 N) aging among all groups. Cyclic fatigue aging decreased the load-bearing capacity (P>0.05) of all tested prostheses, except for the experimental SFRC CAD/CAM and conventional laboratory composite IRFPDs (P>0.05). SEM images showed the ability of discontinuous short fibers in the experimental SFRC CAD/CAM composite to redirect and hinder crack propagation.
CAD/CAM-fabricated IRFPDs made of experimental SFRC blocks showed promising performance in clinical testing in terms of fracture behavior.
评估由实验性短纤维增强复合材料（SFRC）计算机辅助设计/计算机辅助制造（CAD/CAM）块制成的嵌体固位固定局部义齿（IRFPD）在循环疲劳老化前后的断裂行为。
制作五组（每组n = 20）三单位后牙IRFPD。第一组和第二组由实验性SFRC块或二硅酸锂（IPS e.max CAD，IVOCLAR）材料通过CAD/CAM制作而成，第三组由三维打印复合材料（Temp PRINT，GC）组成，第四组和第五组分别由传统实验室用可流动复合材料（Gradia Plus，GC）和商用可流动SFRC（everX Flow，GC）组成。所有IRFPD均用双固化树脂粘结剂（RelyX Ultimate，3M ESPE）粘结到金属夹具中。每组一半的IRFPD（n = 10）进行10000次循环的疲劳老化。其余一半在未进行疲劳老化的情况下进行静态加载直至断裂。载荷垂直施加于颊尖和舌尖的三角嵴之间。使用光学显微镜和扫描电子显微镜（SEM）目视检查断裂模式。数据采用双向方差分析（ANOVA），随后进行Tukey's HSD检验进行统计学分析。
方差分析显示，在所有组中，由实验性SFRC CAD/CAM制成的IRFPD在老化前（2624±463 N）和老化后（2775±297 N）具有最高的（P<0.05）承载能力。循环疲劳老化降低了所有测试修复体的承载能力（P>0.05），但实验性SFRC CAD/CAM和传统实验室复合材料IRFPD除外（P>0.05）。SEM图像显示实验性SFRC CAD/CAM复合材料中的不连续短纤维能够使裂纹转向并阻碍裂纹扩展。
由实验性SFRC块通过CAD/CAM制作的IRFPD在断裂行为方面在临床试验中表现出良好的性能。
