... used for all intra-oral dental x-ray lm size #0, #1, #2 and #3.8) Endodontic instrument safely straddles the subject tooth ... ring.2. Place appropriate size film in instrument with imprinted side of film away form x-ray tube head. - White toward light, place ... facing the bite-blocks bite surface and the x-ray tubehead.- For endo, place the instrument over the tooth, les and clamps, resting ...