A dental cleaning appliance includes a handle, a fluid reservoir for storing a working fluid, and a fluid delivery system for receiving working fluid from the fluid reservoir, and for delivering the working fluid to the teeth of a user. The fluid reservoir is delimited by a wall and a movable member which is moveable relative to the wall to vary the volume of the fluid reservoir. An expansion chamber is located adjacent to the moveable member. The volume of the fluid reservoir decreases, and the volume of the expansion chamber increases, as fluid is supplied to the fluid delivery system during use of the appliance.