Statement of problem

Composite resins and glass-ceramics are both used to restore worn teeth. Which restoration material is more durable is unclear.

Purpose

The purpose of this in vitro study was to evaluate the load to failure of thin composite resins and glass-ceramic restorations on enamel and dentin under increasing repetitive loads.

Material and methods

Glass-ceramic blocks (IPS e.max CAD; Ivoclar AG) were shaped into cylinders (Ø4.0×1.0 mm), crystallized, and adhesively luted to bovine dentin and enamel substrates that were embedded in polymethyl methacrylate (n=20). Identical direct composite resin restorations (Clearfil AP-X; Kuraray Noritake Dental Inc) were made and directly applied on the same substrates (n=20). All specimens were tested in a pneumatic device with a stainless steel ball that provided a stepwise increase of the load (N) starting at 250 N and increasing by 50 N after every 10 000 cycles to a maximum of 1150 N. Failures were detected by a displacement sensor and defined by chipping of restorative material or catastrophic failure.

Results

On dentin, composite resin showed a significantly higher fatigue resistance than glass-ceramic. On enamel, no significant difference was found between the 2 materials.

Conclusions

When bonded to dentin, thin direct composite resin restorations were more durable than glass-ceramics. When bonded to enamel, no difference was found.

中文翻译：

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复合树脂和微晶玻璃对牙本质和牙釉质的抗疲劳性

问题陈述

复合树脂和玻璃陶瓷都用于修复磨损的牙齿。哪种修复材料更耐用尚不清楚。

目的

这项体外研究的目的是评估薄复合树脂和玻璃陶瓷修复体在不断增加的重复载荷下对牙釉质和牙本质的破坏载荷。

材料与方法

玻璃陶瓷块（IPS e.max CAD；Ivoclar AG）被塑造成圆柱体（Ø4.0×1.0 mm），结晶并粘合到嵌入聚甲基丙烯酸甲酯（n = 20）中的牛牙本质和牙釉质基底上。制作相同的直接复合树脂修复体（Clearfil AP-X；Kuraray Noritake Dental Inc）并直接应用于相同的基材（n = 20）。所有样品都在带有不锈钢球的气动装置中进行测试，该装置从 250 N 开始逐步增加载荷 (N)，并在每 10 000 次循环后增加 50 N，最大为 1150 N。位移传感器，由修复材料碎裂或灾难性故障定义。

结果

在牙本质上，复合树脂的抗疲劳性明显高于玻璃陶瓷。在搪瓷上，两种材料之间没有发现显着差异。

结论

当与牙本质粘合时，薄的直接复合树脂修复体比玻璃陶瓷更耐用。当粘合到搪瓷上时，没有发现任何差异。