All the canals were irrigated with 5 ml of 2.5% sodium hypochlorite (Biodinamica, Ibipora, CE, Brazil) between each instrument, and EDTA (Biodinamica) was used before filling the root canals for groups PCrZO, PCrCH, PCZO, PCCH and OTg.
Groups PCZO, PCCH, OTg, PC and OT were prepared in the same way by the same operator, but without leaving coronal tooth structure above the crown margin.
Groups PCrZO, PCrCH, PCZO, PCCH and OTg had their gutta-percha removed at a length equal to 2/3 of the total length of the root using a largo reamer #2 (Dentsply Maillefer, Ballaigues, Switzerland).