Weissman A, et al. - Via collecting medical records and radiographs from patients who had undergone retrograde root canal retreatment (RRR) between 2009 and 2016 and had a 1-year follow-up, researchers evaluated retrospectively the clinical and radiographic outcomes of RRR and identified possible prognostic factors that can affect the outcome using univariate analysis and multivariate logistic regression. A total of 575 patients were included with 721 teeth. Data reported that RRR was successful in 91.8% of cases. None of the prognostic factors (including age, gender, size of periapical radiolucency and isthmus presence) influenced the result significantly. This predictable rate of success was achieved by minimizing the root-end resection and maximizing the length of retrograde preparation.