Abstract: A dental treatment apparatus is presented comprising a container adapted to contain liquid, the container comprise an opening for filling the container and for receiving through it a capsule comprising active materials, the active materials to create chemical reaction that releases gas, an assembly for providing and controlling of pressurized liquid contained in the container, and an assembly for erupting the cover of the capsule. Further presented is a method for pressurizing liquid in a container, the method may comprise providing a capsule into a capsule holding unit, wherein a tearable cover of the capsule is facing an erupting mechanism provided in the capsule holding unit, tightly locking the container, and activating the erupting mechanism by an activation mechanism to erupt the tearable cover, thereby initiating chemical reaction of active materials contained in the capsule with liquid contained in the container. Capsules according to the present invention are also presented.