A device, method, and system are provided for treating the oral cavity. The device includes a mouthpiece suitable for implementing a dental treatment, wherein the mouthpiece includes one or more stock elastomeric dental cover layers suitable for forming and maintaining treatment cavity having a vacuum fluid seal, wherein the dental cover layers includes a layer over the upper teeth and surrounding gums and/or a layer over the lower teeth and surrounding gums, wherein each of the layers includes one or more hardened sections for enabling selected/differential collapsibility when exposed to vacuum pressure； and one or more treatment supply layers wherein the treatment supply layer incorporates a heating unit for heating treatment materials and one or more flow channels in fluid communication with the treatment cavity so that the treatment supply layer can deliver and/or remove one or more treatment fluids from the one or more fluid sealed treatment cavities.
