Periapical Bone Healing after Apicectomy with and without Retrograde Root Filling with Mineral Trioxide Aggregate: A 6-year Follow-up of a Randomized Controlled Trial

IntroductionIn cases of post-treatment periapical disease, retreatment may be necessary. To choose the most appropriate retreatment method, knowledge of the long-term prognosis is important. Surgical endodontic retreatment (SER) is a relevant treatment method. This study assessed changes in outcome from 1 to 6 years after surgery.MethodsSER was performed on teeth randomly allocated to have a MTA root-end filling (MTA group) or smoothing of the orthograde gutta-percha filling after apicectomy (GP group). Patients participating in the 1-year follow-up were reinvited for a 6-year clinical and radiographic examination. Three observers assessed treatment outcome both clinically and radiographically from the 1-year and 6-year follow-up examination.ResultsAt the 6-year follow-up, 39 of 52 teeth were available and examined (75% participation rate). In the MTA group, 16 of 19 teeth (86%) and in the GP group 11 of 20 teeth (55%) were assessed as successful (P = .04). In the MTA group and the GP group, 80% and 90%, respectively, of teeth assessed as successful at the 1-year follow-up remained successful. All unsuccessful teeth in the MTA group (3 teeth) were lost because of vertical root fracture.ConclusionsThe proportion of healed cases was larger in the MTA group than in the GP group at both the 1-year and 6-year follow-up. Findings indicate that a 1-year follow-up may not be sufficient in assessing the long-term outcome of surgical endodontic retreatment. With a longer follow-up, other factors not directly related to the endodontic treatment may be relevant for a successful outcome. This needs further investigation in larger patient samples.