Department of Prosthetic Dentistry, UKR University Hospital Regensburg, 93042 Regensburg, Germany.
Department of Prosthetic Dentistry, UKR University Hospital Regensburg, 93042 Regensburg, Germany.
J Dent. 2018 Jul;74:95-100. doi: 10.1016/j.jdent.2018.05.004. Epub 2018 May 16.
To investigate the edge force of CAD/CAM materials as a function of (a) material, (b) thickness, and (c) distance from the margin.
Materials intended for processing with CAD/CAM were investigated: eight resin composites, one resin-infiltrated ceramic, and a clinically proven lithiumdisilicate ceramic (reference). To measure edge force (that is, load to failure/crack), plates (d = 1 mm) were fixed and loaded with a Vickers diamond indenter (1 mm/min, Zwick 1446) at a distance of 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, and 1.0 mm from the edge. Edge force was defined as a loading force at a distance of 0.5 mm. The type of failure was determined. To investigate the influence of the thickness, all data were determined on 1-mm and 2-mm plates. To test the influence of bonding and an underlying dentin, individual 1-mm plates were bonded to a 1-mm-thick dentin-like (concerning modulus of elasticity) resin composite.
For the 1-mm plates, edge force varied between 64.4 ± 24.2 N (Shofu Block HC) and 183.2 ± 63.3 N (ceramic reference), with significant (p ≤ 0.001) differences between the materials. For the 2-mm plates, values between 129.2 ± 32.5 N (Lava Ultimate) and 230.3 ± 67.5 N (Cerasmart) were found. Statistical comparison revealed no significant differences (p > 0.109) between the materials. Brilliant Crios (p = 0.023), Enamic (p = 0.000), Shofu Blocks HC (p = 0.009), and Grandio Bloc (p = 0.002) showed significantly different edge force between the 1-mm- and 2-mm-thick plates. The failure pattern was either cracking, (severe) chipping, or fracture.
Material, material thickness, and distance from the edge impact the edge force of CAD/CAM materials.
CAD/CAM materials should be carefully selected on the basis of their individual edge force and performance during milling.
研究 CAD/CAM 材料的边缘力作为以下因素的函数：（a）材料，（b）厚度，以及（c）距边缘的距离。
研究了用于 CAD/CAM 加工的材料：八种树脂复合材料、一种树脂渗透陶瓷和一种临床验证的锂硅玻璃陶瓷（参考）。为了测量边缘力（即失效/裂纹的负载），将厚度为 1mm 的板固定，并以 1mm/min 的速度用维氏金刚石压头（Zwick 1446）加载，距离边缘 0.4、0.5、0.6、0.7、0.8、0.9 和 1.0mm。边缘力定义为距离 0.5mm 处的加载力。确定了失效类型。为了研究厚度的影响，所有数据均在 1mm 和 2mm 板上确定。为了测试粘结和基底牙本质的影响，将单独的 1mm 厚的板粘结到类似于牙本质的（关于弹性模量）树脂复合材料 1mm 厚的层上。
对于 1mm 厚的板，边缘力在 64.4±24.2N（Shofu Block HC）和 183.2±63.3N（陶瓷参考）之间变化，材料之间存在显著差异（p≤0.001）。对于 2mm 厚的板，发现的数值在 129.2±32.5N（Lava Ultimate）和 230.3±67.5N（Cerasmart）之间。统计比较显示，材料之间没有显著差异（p>0.109）。Brilliant Crios（p=0.023）、Enamic（p=0.000）、Shofu Blocks HC（p=0.009）和 Grandio Bloc（p=0.002）在 1mm 和 2mm 厚的板之间的边缘力有明显差异。失效模式为裂纹、（严重）碎裂或断裂。
材料、材料厚度和距边缘的距离都会影响 CAD/CAM 材料的边缘力。
应根据 CAD/CAM 材料的单独边缘力和铣削过程中的性能仔细选择材料。
