The present application is directed to a method for isolating a working area in a patient's mouth comprising providing a moldable elastomeric composition, molding the composition to provide a moldable isolation device having a desired shape, making at least one perforation on the isolation device, and positioning the isolation device inside the patient's mouth to isolate the desired working area through the perforation. In such an embodiment, the moldable elastomeric composition comprises a polysiloxane composition.
