Chronic apical periodontitis was diagnosed in tooth 22 of a 45 year old female patient in routine dental investigation. The patient informs of some previous periods with mild pain at the area. A deep distal composite filling had been lost some weeks earlier, but no caries was detected.

The access cavity was prepared with a high speed diamond, the rubber dam applied and the area was disinfected with chlorhexidine/ethanol (0.5 % / 70 %). Size 20 K-file was inserted into the canal and a working length radiograph was taken. The canal was prepared with reamers and Hedstroem files to size 60 / 22.5 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.

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