The present article introduces a rubber dam system developed for the simultaneous isolation of teeth and gingival tissues. The rubber dam device is fabricated from simple, easy-to-find, and inexpensive materials, such as iron-core elastic tube, latex sheets, expanding screws, dental acrylic resin, and glue. Measurements of the dimensions of the maxillas and mandibles of 100 patients indicated that three prefabricated sizes of the device (small, medium, and large) can be applied in the majority of individuals.