Factors Affecting the Endodontic Treatment Outcome

Inclusion Criteria: * patients referred to the private endodontic specialist office for endodontic treatment * written informed consent was obtained prior beginning of the treatment. Exclusion Criteria: * preoperative advanced periodontal disease * prior microsurgical root-end resection performed * apices of the tooth were not clearly discernible on any of periapical radiographs * endodontic treated teeth were extracted for non-endodontic reason * the patient did not attend a follow-up examination.