A prosthetic crown was planned on tooth 35. There were several large restorations on the tooth, which extended to the close proximity of the pulp. Endodontic treatment 'pro prosthesis' was planned. Local infiltration anaesthesia was applied and pulp chamber was perforated with a high-speed diamond with water cooling. Sudden disappearance of the canal shadow in the radiograph indicated ramification of the canal into to apical canals. Similar double canal morphology could be detected also in tooth 34.