The roots were prepared in a crown-down fashion with the TruNatomy™ rotary filing system (Dentsply Sirona, Ballaigues, Switzerland) in accordance with recommended manufacturer instructions. After each instrument change, the root canals were irrigated with 4% NaOCl. All canals underwent a final irrigation of 3 mL of 15% EDTA and 3 mL of 4% NaOCl before being dried with absorbent paper points (Dentsply Sirona, Ballaigues, Switzerland).
The roots were randomly allocated to three treatment groups (n = 13), each to be obturated with a different sealer: either AH Plus Jet (Dentsply DeTrey, Konstanz, Germany) EndoSequence (Brasseler USA, Savannah, GA, USA) or AH Plus Bioceramic Sealer (Dentsply Sirona, Johnson City, TN, USA). From each group, three roots were obturated with their allocated sealers mixed with 0.1% rhodamine B dye (Sigma-Aldrich, St Louis, MO, USA) for confocal laser scanning microscopy (CLSM) analysis. Root canal obturation was performed using a single-cone technique, then stored in 100% relative humidity at 37 °C for 7 days to mimic in vivo conditions to allow for the complete setting of the materials.
The roots were randomly allocated to three treatment groups (n = 13), each to be obturated with a different sealer: either AH Plus Jet (Dentsply DeTrey, Konstanz, Germany) EndoSequence (Brasseler USA, Savannah, GA, USA) or AH Plus Bioceramic Sealer (Dentsply Sirona, Johnson City, TN, USA). From each group, three roots were obturated with their allocated sealers mixed with 0.1% rhodamine B dye (Sigma-Aldrich, St Louis, MO, USA) for confocal laser scanning microscopy (CLSM) analysis. Root canal obturation was performed using a single-cone technique, then stored in 100% relative humidity at 37 °C for 7 days to mimic in vivo conditions to allow for the complete setting of the materials.