Two-Year Healing Success Rates after Endodontic Treatment Using 3D Cleaning Technique: A Prospective Multicenter Clinical Study

Background: Various irrigation techniques for cleansing the endodontic space have been proposed, and internal heating combined with ultrasonic activation (3D cleaning technique) is considered an effective technique. This prospective multicenter clinical study aims to evaluate healing rates for teeth after root canal treatment utilizing the 3D cleaning technique and to report predictive values for success. Material and Methods: Ninety patients referred for a root canal treatment were included. All enrolled patients were treated with the 3D cleaning protocol. Four endodontists performed the clinical procedures and follow-up evaluations. Preoperative, postoperative and follow-up data were gathered from the consented patients. Each patient was assessed for any clinical signs or symptoms. Afterwards, two trained, blinded, and independent evaluators scored the subject's periapical radiographs. This score was made by checking for the presence or absence of apical periodontitis using the periapical index (PAI). Then, the teeth were classified as healing or healed and were considered a success based on a cumulative success rate of healing. Statistical analysis was performed using the Fisher's exact test, Pearson correlation, and logistic regression analyses of the preoperative prognostic factors at a 0.05 significance level. Results: 90 patients were evaluated at two years with a follow-up rate of 97.7%. The cumulative success rate of healing was 95.4%. Eight predicting aspects were identified by employing bivariate analyses. Then, using logistic analyses, the two prognostic significant variables directly correlated to healing were the preoperative presence of periapical index (p value = 0.016). Conclusions: In this two-year clinical study, the cumulative success rate of healing was 95.4% when patients were treated with the 3D cleaning protocol.