Sodium hypochlorite with reduced surface tension does not improve in situ pulp tissue dissolution.
INTRODUCTION
Sodium hypochlorite (NaOCl) solutions with added wetting agents are advertised to dissolve necrotic tissue in root canals faster than their counterparts 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 commercially 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 solution 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 correlation 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 irrespective of the solution.
['De-Deus|Gustavo|G|', 'de Berredo Pinho|Marco André|MA|', 'Reis|Claudia|C|', 'Fidel|Sandra|S|', 'Souza|Erick|E|', 'Zehnder|Matthias|M|']
D000328:Adult D019412:Anatomy, Cross-Sectional D003782:Dental Pulp D003786:Dental Pulp Cavity D006801:Humans D006863:Hydrogen-Ion Concentration D008422:Materials Testing D012388:Root Canal Irrigants D018915:Root Canal Preparation D012973:Sodium Hypochlorite D012995:Solubility D013500:Surface Tension D013997:Time Factors D019227:Tooth Apex D014092:Tooth Root D017155:Wettability D014906:Wetting Agents
sodium hypochlorite surface tension pulp tissue Chlor-XTRA debridement oval shaped root canals