ABSTRACT
Aim and Objective: The effects of four endodontic irrigants and on a smear layer created by hand and rotary instrumentation were evaluated in vitro in the middle and apical thirds of root canals. Materials and Methods: Forty eight mature extracted mandibular premolar teeth with a single root canal and a closed apex were distributed randomly into four groups of 12 teeth each. Whilst cleaning and shaping up to size F5 using Protaper Universal System, the root canals were irrigated with 3 mL of 5.25% NaOCl, between each file size. Group 1 (G1) were irrigated with a final flush of QMix 2in1. The teeth in group 2 (G2) were irrigated with a final flush of 0.2%Chitosan, group 3 (G3) with Smear Clear and group 4 (G4) with Glyde. The teeth were split longitudinally and prepared for examination by scanning electron microscopy. Results: Specimens irrigated with a final flush of Glyde (G4) or 0.2%Chitosan (G2) were cleaner than with QMix and Smear Clear, showing very clean root canal surfaces in the middle one-third but in the apical one-third the smear layer was not completely removed, especially at the openings of the dentinal tubules. Statistical analysis showed no significant difference in the cleanliness of root canal wall between G1, G2, G3 and G4. Conclusion: Irrigation with QMix 2in1, Smear Clear, 0.2%Chitosan, and Glyde and 6% did not remove all the smear layer from the root canal system. All these irrigants showed less effectiveness in removal of smear layer from apical 3rd. Glyde showed maximum efficacy in removal of removal of smear layer followed by 0.2%Chitosan, Smear Clear and then QMix 2in1.