The canal was perforated with a high speed diamond, the rubber dam applied and the area was disinfected with chlorhexidine/ethanol (0.5 % / 70 %). Size 15 K-file was inserted into the canal to the length previously measured from the preoperative radiograph and a working length radiograph was taken. The canal was prepared with reamers and Hedstroem files to size 60 / 21 mm, with constant irrigation with 0.5 % sodium hypochorite. At the end the canal was irrigated with 17 % neutral EDTA and dried with paper points. The canal was filled with calcium hydroxide and sealed with a tight temporary topfilling.