Department of Oral Rehabilitation, School of Dentistry, University of Otago, Dunedin, New Zealand.
J Prosthodont. 2011 Dec;20(8):613-20. doi: 10.1111/j.1532-849X.2011.00760.x. Epub 2011 Oct 21.
The purpose of this in vitro study was to evaluate porcelain cracking induced by abrasive grinding with a conventional dental air turbine and abrasive diamond burs.
Four commercially available porcelains were examined-Wieland ALLUX, Wieland ZIROX, IPS e.max Ceram, and IPS Empress Esthetic Veneering porcelain. Sixty discs of each porcelain type were fabricated according to manufacturer instructions, followed by an auto-glaze cycle. Abrasive grinding using fine, extra-fine, and ultra-fine diamond burs was carried out, using a conventional dental air turbine. The grinding parameters were standardized with regard to the magnitude of the force applied, rotational speed of the diamond bur, and flow rate of the water coolant. A testing apparatus was used to control the magnitude of force applied during the grinding procedure. The ground surfaces were then examined under scanning electron microscope.
Cracking was seen for all porcelain types when ground with the fine bur. Cracking was not seen for specimens ground with the extra-fine or the ultra-fine bur.
Wet abrasive grinding with a conventional dental air turbine and fine grit diamond burs has the potential to cause cracking in the four porcelain types tested. Similar abrasive grinding with smaller grit size particles does not cause similar observable cracking.
本体外研究的目的是评估常规牙科涡轮机和研磨金刚石磨头对瓷裂的影响。
本研究检测了四种市售瓷-Wieland ALLUX、Wieland ZIROX、IPS e.max Ceram 和 IPS Empress Esthetic Veneering 瓷。根据制造商的说明制作了每种瓷类型的 60 个圆盘，然后进行自动上釉循环。使用常规牙科涡轮机进行精细、超精细和超细金刚石磨头的研磨。研磨参数与施加力的大小、金刚石磨头的转速和水冷却剂的流量标准化。测试装置用于控制研磨过程中施加力的大小。然后在扫描电子显微镜下检查研磨表面。
当使用细磨头研磨时，所有瓷类型都出现了裂纹。使用超细或超粗磨头研磨的样本没有出现裂纹。
使用常规牙科涡轮机和细粒度金刚石磨头进行湿式研磨有导致所测试的四种瓷裂的潜在风险。使用较小粒度的类似研磨不会导致类似的可观察到的裂纹。
