Faculty of Dentistry, Department of Oral Rehabilitation, University of Otago, Dunedin, New Zealand.
Department of Applied Sciences, University of Otago, Dunedin, New Zealand.
J Esthet Restor Dent. 2020 Jun;32(4):424-432. doi: 10.1111/jerd.12584. Epub 2020 Apr 9.
This in vitro study aims to evaluate load-to-failure of ceramic veneers with butt joint (BJ) and feathered edge (FE) incisal preparation designs, and to correlate these results to the failure mode of the restorations.
One hundred and forty-eight typodont teeth (customized Nissin A25A-UL19B) were divided into two different preparation configurations BJ and FE and two different loading angulations, 0° and 20°. Lithium disilicate ceramic veneers (IPS e.max CAD, Ivoclar Vivadent) were milled using computer-aided-design-and-computer-aided-manufacturing (CAD/CAM) techniques. Veneers were bonded to typodont teeth with resin cement (IPS Variolink Esthetic, Ivoclar Vivadent). Each group was loaded at the incisal edge using an Instron Universal Testing Machine at a crosshead speed of 0.01 mm/s till failure.
Pairwise comparison showed veneers from the BJ groups had a significantly higher load-to-failure value compared to the FE groups. Veneers with a FE preparation design loaded at 20° angulation had the lowest load-to-failure value.
Within the limitations of the present study, both incisal preparation designs and loading angulations have significant effects on the load-to-failure values of ceramic veneers. BJ group exhibits a significantly higher load-to-failure value compared to the FE group.
BJ incisal preparation is preferred over FE preparation design.
本体外研究旨在评估具有对接（BJ）和羽毛边（FE）切缘预备设计的陶瓷贴面的失效负荷，并将这些结果与修复体的失效模式相关联。
将 148 颗定制的人工牙（Nissin A25A-UL19B）分为两种不同的预备构型（BJ 和 FE）和两种不同的加载角度（0°和 20°）。使用计算机辅助设计和制造（CAD/CAM）技术加工二硅酸锂陶瓷贴面（IPS e.max CAD，义获嘉伟瓦登特）。使用树脂水门汀（IPS Variolink Esthetic，义获嘉伟瓦登特）将贴面粘接到人工牙上。使用 Instron 万能试验机以 0.01mm/s 的十字头速度在切缘加载每个组，直至失效。
两两比较显示，BJ 组的贴面失效负荷值明显高于 FE 组。以 20°角度预备的 FE 设计贴面的失效负荷值最低。
在本研究的限制范围内，切缘预备设计和加载角度都对陶瓷贴面的失效负荷值有显著影响。BJ 组的失效负荷值明显高于 FE 组。
BJ 切缘预备优于 FE 预备设计。
