Load-bearing capacity of CAD/CAM 3D-printed zirconia, CAD/CAM milled zirconia, and heat-pressed lithium disilicate ultra-thin occlusal veneers on molars
Load-bearing capacity of CAD/CAM 3D-printed zirconia, CAD/CAM milled zirconia, and heat-pressed lithium disilicate ultra-thin occlusal veneers on molars
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DOI：
10.1016/j.dental.2020.01.016
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发表时间：
2020-04-01
期刊：
影响因子：
5
通讯作者：
Muhlemanna, S.
中科院分区：
文献类型：
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作者：
Ioannidis, A.;Bomze, D.;Muhlemanna, S.
目标.将3D打印氧化锆制成的超薄咬合贴面的承载能力与通过CAD/CAM铣削氧化锆或热压二硅酸锂制造这些重建获得的咬合贴面的承载能力进行比较。在60颗离体人磨牙上，去除咬合釉质并延伸到牙本质中。数字化设计0.5mm厚的咬合贴面。根据修复材料和咬合面制作技术的不同，将标本分为3组（每组20个）。(1)3DP：3D打印氧化锆（Lithoz）;（2）：CAM：研磨氧化锆（Ceramill Zolid FX）;（3）HPR：热压二硅酸锂（IPS e.max Press）。在处理程序之后，将所述预处理物粘结到处理的牙齿上。此后，通过暴露于循环疲劳和温度变化，在咀嚼模拟器中对所有样本进行老化。随后，对样本进行静态加载，并测量将最大载荷降低20%并引发裂纹所需的载荷（F-初始）和使样本断裂所需的载荷（F-最大）。应用Kruskal-Wallis（KW）检验和Wilcoxon-Mann-Whitney检验（WMW：p < 0.05）比较组间差异。3DP、CAM和HPR组的中位F初始值分别为1 '650 N、1' 250 N和500 N。所有三组之间的差异具有统计学显著性（KW：p < 0.0001）。3DP组的F max中值为2 '026 N，CAM组为1' 500 N，HPR组为1 '555 N。3DP和CAM之间存在显著差异（WMW：p = 0.0238）。(C)2020年牙科材料学院。爱思唯尔公司出版All rights reserved.
Objectives. The load-bearing capacity of ultra-thin occlusal veneers made of 3D-printed zirconia were compared to the ones obtained by fabricating these reconstructions by CAD/CAM milling zirconia or heat-pressing lithium- disilicate.Methods. On 60 extracted human molars, the occlusal enamel was removed and extended into dentin. Occlusal veneers of 0.5 mm thickness were digitally designed. The specimens were divided into 3 groups (n = 20 each) differing in the restorative material and the fabrication technique of the occlusal veneer. (1) 3DP: 3D-printed zirconia (Lithoz); (2): CAM: milled zirconia (Ceramill Zolid FX); (3) HPR: heat-pressed lithium disilicate (IPS e.max Press). After conditioning procedures, the restorations were adhesively bonded onto the conditioned tooth. Thereafter, all specimens were aged in a chewing simulator by exposure to cyclic fatigue and temperature variations. Subsequently the specimens were statically loaded and the load which was necessary to decrease the maximum load by 20% and initiate a crack (F-initial) and the load which was needed to fracture the specimen (F-max) were measured. Differences between the groups were compared applying the Kruskal-Wallis (KW) test and the Wilcoxon-Mann-Whitney-Test (WMW: p < 0.05).Results. The median F-initial values for the groups 3DP, CAM and HPR were 1'650 N, 1'250 N and 500 N. The differences between all three groups were statistically significant (KW: p < 0.0001). The median F max values amounted to 2'026 N for the group 3DP, 1'500 N for the group CAM and 1'555 N for the group HPR. Significant differences were found between 3DP and CAM (WMW: p = 0.0238). (C) 2020 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.