Introduction: The aim of this study was to compare the percentage of the residual gutta-percha-occupied area (PRGPA) in root canals after retreatment using ProTaper retreatment files (Dentsply Maillefer, Ballaigues, Switzerland) with or without the additional use of Self-Adjusting Files (SAFs; ReDent-Nova, Ra'anana, Israel).
Methods: Root canals in 33 curved mesiobuccal roots of the first maxillary molars were cleaned and filled with gutta-percha and AH26 sealer (Dentsply De Trey, Johnson City, TN). Retreatment instrumentation was performed in 28 roots with ProTaper retreatment files and Hedström files.