title: Sodium hypochlorite with reduced surface tension does not improve in situ pulp tissue dissolution.
abstract: BACKGROUND
  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.
authors.affiliation: Dental Sciences Course, Grande Rio University, Rio de Janeiro, Rio de Janeiro, Brazil. endogus@gmail.com
authors.forename: Gustavo
authors.initials: G
authors.lastname: De-Deus
authors.forename: Marco André
authors.initials: MA
authors.lastname: de Berredo Pinho
authors.forename: Claudia
authors.initials: C
authors.lastname: Reis
authors.forename: Sandra
authors.initials: S
authors.lastname: Fidel
authors.forename: Erick
authors.initials: E
authors.lastname: Souza
authors.forename: Matthias
authors.initials: M
authors.lastname: Zehnder
mesh_terms: D000328:Adult; D019412:Anatomy, Cross-Sectional; D003782:Dental Pulp / Q000033:anatomy & histology / Q000187:drug effects*; D003786:Dental Pulp Cavity / Q000033:anatomy & histology / Q000187:drug effects; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D012388:Root Canal Irrigants / Q000737:chemistry / Q000494:pharmacology*; D018915:Root Canal Preparation / Q000379:methods; D012973:Sodium Hypochlorite / Q000737:chemistry / Q000494:pharmacology*; D012995:Solubility; D013500:Surface Tension; D013997:Time Factors; D019227:Tooth Apex / Q000033:anatomy & histology / Q000187:drug effects; D014092:Tooth Root / Q000033:anatomy & histology / Q000187:drug effects; D017155:Wettability; D014906:Wetting Agents / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D012388:Root Canal Irrigants; D014906:Wetting Agents; D012973:Sodium Hypochlorite
keywords: Chlor-XTRA; debridement; oval shaped root canals; pulp tissue; sodium hypochlorite; surface tension