Success Rate of Single- versus Two-visit Root Canal Treatment of Teeth with Apical Periodontitis: A Randomized Controlled Trial

Introduction The aim of this study was to evaluate the outcome of single- versus 2-visit root canal treatment of teeth with apical periodontitis after a 2-year follow-up period. Methods Three hundred maxillary and mandibular nonvital teeth with apical periodontitis were treated in either a single visit or 2 visits. The main inclusion criteria were radiographic evidence of apical periodontitis (minimum size ≥2.0 × 2.0 mm) and a diagnosis of pulpal necrosis confirmed by a negative response to hot and cold tests. Radiographically, all teeth showed small and irregular periapical radiolucencies before treatment. The canals were enlarged with LightSpeedLSX (Discus Dental, Culver City, CA) root canal instruments to a final apical preparation size #60 for anterior and premolar teeth and size #45 to #55 for molars. The EndoVac negative-pressure irrigation system (Discus Dental) was used for disinfecting irrigation, and all canals were filled by lateral compaction of gutta-percha and Sealapex sealer (SybronEndo, Orange, CA). The healing results were clinically and radiographically evaluated 2 years postoperatively. Results Of the 300 teeth treated, 18 were lost to follow-up, 9 in the 2-visit group and 9 in the 1-visit group. Of the 282 teeth studied, the randomization procedure had allocated 146 teeth to 1-visit treatment and 136 teeth to 2-visit treatment. Teeth with symptoms of persisting periapical inflammation were scored as not healed. Teeth with a reduced periapical rarefaction were judged as uncertain. Teeth with complete restitution of the periodontal contours were judged as healed. In the 1-visit group, 141 of 146 teeth (96.57%) were classified as healed as compared with 121 (88.97%) of 136 teeth in the 2-visit group. Eleven cases were classified as uncertain in the 2-visit group (8.08%) compared with 4 (2.73%) in the 1-visit group. Two of 10 teeth in the 2-visit group presented with pain before the 2-year follow-up and were classified as not healed. The hypothesis tests were conducted at the 0.05 level of significance. Statistical analysis of the healing results did not show any significant difference between the groups ( P = .05). Conclusions Several factors play an important role in the decision-making process of 1- versus 2-visit endodontics. Among these are objective factors like preoperative diagnosis, the ability to obtain infection control, root canal anatomy, procedural complications, and subjective factors like patients' signs and symptoms. This study provided evidence that with a treatment protocol with instrumentation to predefined larger apical instrumentation sizes and irrigation with a negative apical pressure system can lead to healing in cases of apical periodontitis, which is a significant finding compared with more dated studies that showed average healing of apical periodontitis cases. With the given sample size, there was no statistically significant difference between the 2 treatment modalities.