Spencer Kevin R, Ferguson John W, Smith Andrew C, Palamara Joseph E A
School of Dental Science, University of Melbourne, Parkville, Melbourne, Australia.
J Oral Maxillofac Surg. 2004 Apr;62(4):473-8. doi: 10.1016/j.joms.2003.07.008.
This experimental study was designed to examine whether screw head design influenced the angle of application of a screwdriver at which failure of engagement or stripping of the screw head occurred.
Four different screw head designs (slot, cross, square, star) were tested in a custom-made jig that was designed to enable the screws to be tested over a range of angles of application of the respective screwdrivers, to determine whether the screw head design influenced the torque value at which the screw head stripped or failure of driver engagement occurred.
The results fell clearly into 2 groups: The slot and cross designs gave the highest torque values at all angles, while the torque values for the square and star designs dropped to a low value with increasing angulation between the screw and driver. These differences were significant (P <.001).
Although this experimental situation cannot be entirely extrapolated to the clinical situation, it indicates that the slot or cross design may offer an advantage in regions of difficult access where the angulation of the screwdriver to the screw may of necessity be increased.
本实验研究旨在检验螺丝刀头设计是否会影响螺丝刀应用角度，在此角度下会出现螺丝刀头啮合失败或螺丝头滑丝的情况。
在一个定制夹具中测试四种不同的螺丝刀头设计（一字槽、十字槽、方头、星型），该夹具旨在使螺丝能够在相应螺丝刀的一系列应用角度下进行测试，以确定螺丝刀头设计是否会影响螺丝头滑丝或螺丝刀啮合失败时的扭矩值。
结果明显分为两组：一字槽和十字槽设计在所有角度下都给出了最高扭矩值，而方头和星型设计的扭矩值随着螺丝与螺丝刀之间角度的增加而降至低值。这些差异具有统计学意义（P <.001）。
虽然这种实验情况不能完全外推到临床情况，但它表明在难以操作的区域，当螺丝刀与螺丝的角度可能需要增加时，一字槽或十字槽设计可能具有优势。
