Efficacy of different irrigants in the removal of calcium hydroxide from root canals

Rödig T, Vogel S, Zapf A, Hülsmann M. Efficacy of different irrigants in the removal of calcium hydroxide from root canals. International Endodontic Journal. 43, 519–527, 2010. Aim To compare the efficacy of different solutions (1% sodium hypochlorite, 10% citric acid and 20% EDTA) in the removal of calcium hydroxide from root canals. Methodology One hundred single‐rooted maxillary incisors were prepared to size 50 and split longitudinally. Two standardized grooves were cut into the apical and coronal part of the root canal dentine and filled with calcium hydroxide. The reassembled teeth were irrigated with a syringe and a size 30 needle using the following irrigants: (i) 20% EDTA, (ii) 10% citric acid, (iii) 1% NaOCl, (iv) 10% citric acid + 1% NaOCl, (v) 20% EDTA + 1% NaOCl and (vi) water (control). Volume of irrigant was 20 mL in each group, and irrigation time was 5 min. Evaluation of cleanliness of the blinded specimens was performed by two calibrated observers under a microscope with 30× magnification using a four‐grade scoring system as described by van der Sluis et al. (2007). Statistical evaluation was performed using a SAS‐macro for non‐parametric multifactorial analysis (P