Siegel S C, von Fraunhofer J A
Department of Restorative Dentistry, School of Dentistry, University of Maryland, Baltimore 21201, USA.
J Prosthodont. 1999 Mar;8(1):3-9. doi: 10.1111/j.1532-849x.1999.tb00002.x.
The cutting efficiency of diamond dental burs using different handpiece loads was evaluated against simulated enamel, a machinable glass ceramic (Macor).
An ultra-high-speed dental handpiece was mounted in a frictionless bearing so that the pressure applied at the contact interface between the dental bur and the cutting substrate was controlled. One type of coarse- and two types of medium-grit diamond burs were studied. Handpiece loads of 44, 91.5, and 183 g were applied at the bur/Macor interface, and cutting efficiency was determined as the amount of Macor removed in ten 30-second-duration cuts that were 4 mm in length. The data were analyzed by one-way ANOVA and a post-hoc Scheffé test at an a priori alpha = 0.05.
Cutting efficiency depended on both the diamond grit of the bur and the load applied to the handpiece.
The pressure used by most dentists, about 100 g at the bur tip, appears to be optimal for medium-grit burs. If the pressure applied to the handpiece is markedly increased, there was no increase in cutting efficiency for medium-grit burs. In contrast, an increased handpiece pressure raises the cutting efficiency of coarse-grit burs but the effect of this enhanced rate of cutting on the pulpal tissues is uncertain. Cutting efficiency also appeared to be dependent on debris accumulation between the diamond chips.
针对模拟牙釉质（一种可加工的玻璃陶瓷，Macor），评估使用不同机头负载的金刚石牙科车针的切割效率。
将一台超高速牙科机头安装在无摩擦轴承中，以便控制车针与切割底物接触界面处施加的压力。研究了一种粗粒度和两种中粒度的金刚石车针。在车针/Macor界面处施加44、91.5和183克的机头负载，并将切割效率确定为在十个长度为4毫米、持续时间为30秒的切割过程中去除的Macor量。数据通过单因素方差分析和事后Scheffé检验进行分析，预先设定的α = 0.05。
切割效率既取决于车针的金刚石粒度，也取决于施加在机头上的负载。
大多数牙医使用的压力，即在车针尖端约100克，似乎对中粒度车针而言是最佳的。如果显著增加施加在机头上的压力，中粒度车针的切割效率不会提高。相比之下，增加机头压力会提高粗粒度车针的切割效率，但这种提高的切割速度对牙髓组织的影响尚不确定。切割效率似乎还取决于金刚石颗粒之间的碎屑堆积。
