The application of the rubber dam (dental dam) is indicated in endodontics and for restorative dental treatments involving the acid-etch technique. The frequency of the technique's use varies significantly according to individual circumstances, and is generally too low given its advantages. One possible reason for many dentists' reluctance to use it could be frustrating results in the past with technically difficult applications. Such conditions arise, for example, when the taut rubber dam sheet exerts too much pull on the rubber dam clamps, causing them (and the entire rubber dam) to come loose. Particularly susceptible here are clamps attached to molars. This undesired tension results from stretching the rubber dam material--a necessary step--for attaching the sheet to the traditional rubber dam frame. As an alternative, a new easy-to-use rubber dam frame (Safe-T-Frame) has been developed that offers a secure fit without stretching the rubber dam sheet. Instead, its "snap-shut" design takes advantage of the clamping effect on the sheet caused when its two mated frame members are firmly pressed together. In this way the sheet is securely attached, but without being stretched. Held in this manner, the dam sheet is under less tension, and hence, exerts less tugging on clamps--especially on those attached to molars. Even in cases where there are no distinct anatomic undercuts, this lack of tension in the sheet eases isolation procedures and permits the use of standard rubber dam clamps. As a further benefit, the frame's raised edging provides a barrier around the sheet, which prevents small amounts of fluids from escaping. This contributes to greater patient comfort.