The aim of this prospective cohort observational study is: (i) to assess the endodontic treatment outcome in a private specialist endodontic office in Slovenia; (ii) to estimate the effect of various pre-, intra- and postoperative factors onto 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.

The sample population will include patients who are referred from a general dental practices in Slovenia to a private specialist endodontic practice for endodontic treatment, from the beginning of January 2008 on. All patients will be over 18 years of age at the beginning of the endodontic treatment and will attent a follow-up examination at least 1-4 years after endodontic treatment.

Teeth will not be included in the study if (i) they have preoperative advanced periodontal disease, (ii) prior microsurgical root-end resection was performed, or (iii) the apex / apices of the tooth are not clearly discernible on any of the periapical radiographs.

Teeth will be excluded from the study if (i) they will be extracted for non-endodontic reason or (ii) the patient will not attend a follow-up examination.

anonymised IPD that uderlie the results in the publication will we shared to other researcher on reasonable request

anonymised data will be available on request for 1 year after the publication of the study report

contacting the principal investigator by e-mail