Abstract: An electric toothbrush includes a handpiece and a mountable attachment. The attachment includes a working head and a coupling member which is joined to the working head and connectable to the toothbrush handpiece by positive and/or frictional engagement. The attachment can be an attachment brush for dental cleansing, or for interproximal cleaning devices, such as gum massage heads or other attachment tools for performing similar tasks in the oral cavity. The coupling member is braced against the toothbrush handpiece, to provide a low to zero-play connection which accommodates production tolerances. At least one pivot lever or toggle joint is provided for clamping the coupling member upon the toothbrush handpiece.