The endo-perio lesion may be defined as an infrabony, marginal pocket communicating with an inflam-mation of pulpal origin. In clinical practice, a separate endodontic and periodontal diagnosis is made,whereas treatment outcome eventually confirms the diagnosis of an endo-perio lesion. The treatmentprognosis of such teeth is poorly understood, due to diagnostic uncertainties. The purpose of this studywas to assess the 2-year survival of teeth with an endo-perio diagnosis. A total of 3,700 cases werereviewed. Inclusion criteria for the test group were teeth that had been endodontically treated for apulpal/apical condition and showed severe periodontal involvement with pocket depth >=6 mmand/or furcation involvement. Exclusion criteria were file or root fracture, accidental perforation to theperiodontium during an endodontic procedure, and internal or external root resorption. One hundredteeth that had been endodontically treated due to pulp necrosis, pulpitis and/or apical periodontitiswithout any periodontal involvement were used as a control group. One hundred and thirty-four teethcomplied with the inclusion criteria. The results showed that 20/134 (15%) of teeth in the test grouphad been extracted after 1 year and 25/134 (19%) after 2 years. The extraction rate was significantlyhigher for teeth with chronic apical periodontitis (27%), as compared with teeth without an apicallesion (10%). None of the control teeth had been extracted after 2 years. Periodontally involved teethare at high risk of being extracted after endodontic therapy, and the risk increases with increasing sever-ity of the endodontic diagnosis.
Keywords: endodontic therapy, endo-perio lesions, periodontal therapy