TY JOUR TI ANALYSIS OF THE CAUSES OF FAILURE OF ENDODONTIC TREATMENT AND THE CAUSES OF TOOTH EXTRACTION WITH A DIAGNOSIS OF CHRONIC APICAL PERIODONTITIS KW apical periodontitis KW a survey of dentists KW irrigation methods KW tooth extraction KW endodontic treatment JO Actual problems in dentistry AU Kuratov, I.A. AU Nagaeva, M.O. AU Korneeva, M.V. AU Surkov, M.A. PY 2019 IS 15 PB TIRAZH Publishing House