A knife-holder for disposable blades designed for gingival surgery.

A GINGIVECTOMY knife-holder for disposable blades made on the same principles as the needle-holder has been developed. This knife-holder has all the advantages of the ordinary gingivectomy knives, and in addition it holds a working end of razor-blade sharpness. Dental manufacturing companies are invited to start the produc­ tion of the knife-holder. The knives used for gingival surgery must be angled to get access to all the places in the two jaws. As far as the ordinary gingivectomy knives are concerned, a variety of excellent designs are available. Less successful attempts have been made to produce a knife-holder for disposable blades. The knife-holder to be described was developed by the author in 1968, and it has been used in practice since then. Over the years, several improvements have been made. The prototype shown in Fig. 1 has all the advantages of the classical gingivectomy knives as far as angling of the blade is concerned. In addition, it holds a working end of razor-blade sharpness, which is an unquestionable advantage. The knife-holder in Figure 1 was modified from one of the many needle-holders which can be bought in the medical and dental supply houses. As may be seen, with the knife blade in the vertical plane it can be held at an angle of about 45°. A disposable blade with double edge is fixed in the knife-holder (Fig. 2), and the unwanted part of it is broken off by means of an ordinary needle-holder or a pair of tongs. As a rule, the working end of the blade should be made as short as possible to avoid interference with the tongue and the cheeks, but long enough to penetrate the full thickness of the tissue to be exciced. In practice this means that 4 to 7 mm of the end of the blade should stick out from the knife-holder. The broken end of the blade should be hidden by the blade-holder to avoid injuring the tongue or cheeks. Whereas the angle of the blade to the handle is fixed at 45° in the vertical plane (Fig. 3 A) , in the horizontal plane this angle can be changed within a range of about 250° (Fig 3B) This is a substantial advantage which can be fully made use of during surgical procedures because it requires very little time to change the position of the blade. The lock of the blade-holder is disengaged, the blade is adjusted to the desired angle, and the lock is instantly re-engaged; this will take no more than 2 to 4 seconds. The experienced operator realizes how conven­ ient it is to work with a knife which has the right angle to the teeth and interdental spaces in any area.