IEJ MAIO 2010 - Efficacy of different irrigants in the removal of calcium hydroxide from root canals

Efficacy of different irrigants in the removal of calcium hydroxide from root canals
Volume 43 Issue 6, Pages 519 - 527

T. Rödig , S. Vogel , A. Zapf & M. Hülsmann

KEYWORDS
calcium hydroxide • chelator • citric acid • EDTA • sodium hypochlorite

ABSTRACT
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 < 0.05).

Results
The best results were found for irrigation with EDTA and citric acid, whereas NaOCl and water showed the least effect. The combinations of irrigants did not result in improvement in terms of cleanliness.

Conclusions
None of the irrigants nor their respective combinations were able to completely remove the calcium hydroxide. Chelating agents such as citric acid and EDTA showed the best results. The combination of chelators and NaOCl did not result in significant improvement of calcium hydroxide removal.

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.