Joe August 2013 - Sodium Hypochlorite with Reduced Surface Tension Does Not Improve In Situ Pulp Tissue Dissolution

Sodium Hypochlorite with Reduced Surface Tension Does Not Improve In Situ Pulp Tissue Dissolution


Gustavo De-Deus, DDS, MSc, PhD,* Marco Andr e de Berredo Pinho, DDS, MSc, PhD,† Claudia Reis, DDS, MSc, PhD,‡ Sandra Fidel, DDS, MSc, PhD,† Erick Souza, DDS, MSc, PhD,† and Matthias Zehnder, DDS, PhD§ 

Abstract

Introduction: Sodium hypochlorite (NaOCl) solutions with added wetting agents are advertised to dissolve necrotic tissue in root canals faster than their counter- parts without a lowered surface tension. This was tested in the current study, and the null hypothesis formulated was that there was no difference between a commer- cially available NaOCl solution with a lowered surface tension (Chlor-XTRA; Vista Dental Products, Racine, WI) and a counterpart containing the same amount of available chlorine without added wetting agents regarding the soft tissue that remains in oval-shaped canals after mechanical preparation and irrigation. Methods: Formerly vital extracted teeth (N = 44, 22 pairs) with similar anatomy were radiographically paired and chemomechanically prepared. In 1 tooth from each pair, a 5.25% NaOCl solution with reduced surface tension was used; in the other, a pure, technical-grade NaOCl solu- tion of 5.25% was used. The percentage of remaining pulp tissue (PRPT) was histologically assessed in root cross- sections. The non-Gaussian raw data were subjected to Kruskal-Wallis and Mann-Whitney U tests to verify the respective effect of the cross-section level and solution on the PRPT. The relationship between the cross-section level and the PRPT was estimated by the Spearman corre- lation test. The alpha-type error was set at 5%. Results: The cross-section level significantly influenced the PRPT (P < .05), whereas the PRPT was not influenced by the solution used (P > .05). A significant inverse correlation was found between the cross-section level and the PRPT (P < .05, r = 0.330). The lower the distance to the apex, the higher the PRPT regardless of the solution used. Conclusions: Contrary to the advertised statement, the dental solution with a reduced surface tension did not dissolve vital pulp tissue in oval root canals any better than a conventional NaOCl solution of similar strength. Closer to the apex, pulp tissue dissolution is less efficient irre- spective of the solution. (J Endod 2013;39:1039–1043)

Key Words

Chlor-XTRA, debridement, oval shaped root canals, pulp tissue, sodium hypochlorite, surface tension

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