A toothbrush having an applicator for applying an oral care material to a users oral cavity. In one aspect, the toothbrush comprises a body comprising a handle portion and a head portion; a plurality of tooth cleaning elements extending from the head portion; and a treatment device detachably coupled to the body so as to be alterable between a storage state and a use state, the treatment device comprising: a housing; a store of an oral care material in the housing; an applicator fluidly coupled to the store of the oral care material; and a bite guard protruding from the housing adjacent the applicator.