Rubber dam clamps

There is a vast range of shapes and sizes of rubber dam clamps, supposedly to suit every possible tooth and situation. In fact, this merely causes confusion, as an ill-fitting clamp may be quite unsatisfactory, and dislodge during treatment. When properly fitted, a clamp should have four point contact with the tooth. If not, it will either rock back and forward or dislodge completely.

Clamps are described as being either  active , where the jaws slope downwards and positively slide into cervical undercuts, or  passive  when they tend to remain where placed. They may also be either winged or wingless, depending upon the chosen method of application.
The size 8A clamp is described by the manufacturers as a  universal retentive molar clamp .It is an active clamp, and fits every molar tooth, even when these are quite broken down. The author would suggest therefore that all the other designs merely confuse the issue, and until the operator is very experienced only this clamp is used for all molar teeth. Likewise, the size 1 fits virtually all premolars (Fig. 6). If passive clamps are preferred size 0 or 00 are suitable for premolars, although they will not be as retentive. Rather than place aggressive clamps on anterior teeth, it is usually kinder to use interproximal wedges, either pieces of rubber dam or a commercial product such as  Wedgets  (Fig. 7). It is often easier to isolate several anterior teeth, giving a clear operating field.

Rubber dam stamp

This is another piece of equipment now largely superseded. For single tooth isolation, a hole punched 2 cm diagonally from the middle of the sheet gives universal dam. The hole is simply orientated to the quadrant under treatment. For multiple isolation, it is preferable to hold the dam against the teeth to be isolated, and mark the centre of each tooth with a pen, as shown in Figure 3. The holes will then be punched in accordance with the patient s dentition and not with an arbitrary stamp. 

Rubber dam punch

Fig. 3  For multiple isolation, the position of the holes to be punched may be marked by holding the rubber dam against the teeth.
Much of the equipment for rubber dam has been rationally modified. The revolving plate on the old punch was rarely used, as a single size hole will really fit all teeth. When the table was moved it frequently led to eccentric wear of the pin, which then did not cut a clean hole. The defect in the cut may cause the dam to split when stretched out. The new rubber dam punches are single table (Fig. 2) and should always cut a clean hole.