title: The effect of temperature and pH variations on the surface tension of EDTA solutions.
abstract: BACKGROUND
  Surface tension of a liquid is one of the major factors that affect the wetting of a solid. The reduction in surface tension could improve the contact of irrigants with the dentinal walls of the root canal system. This in vitro study was conducted to evaluate the effect of pH and temperature variations on the surface tension of EDTA solutions.
  
  
  METHODS
  Three solutions, 17% EDTA, REDTA, and EDTA-T, were prepared and adjusted to have a pH of 5.5, 7.5, and 10.5. The surface tension of the test solutions was measured at 22 °C by the pendant drop technique, and the measurement was repeated after heating the solution at 37 °C. Differences among the experimental groups were statistically analyzed using three-way analysis of variance followed by the Bonferroni test for pair-wise comparison.
  
  
  RESULTS
  The results of this study showed that there were significant differences in the surface tension values of solutions depending on the pH and temperature (P < .001). The surface tension level of the EDTA solution dramatically decreased when surfactant was added to the EDTA solution in both pH and temperature variations (P < .001). The increased temperature significantly altered the surface tension value at a pH of 5.5 of all EDTA solutions, at a pH of 7.5 of EDTA and REDTA solutions, and at a pH of 10.5 of only REDTA solution (P < .01).
  
  
  CONCLUSIONS
  It was concluded that the surface tension of EDTA with and without surfactant is influenced by pH and temperature.
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Hacettepe University, Ankara, Turkey. dtzeliha@gmail.com
authors.forename: Zeliha
authors.initials: Z
authors.lastname: Yılmaz
authors.forename: Sevinc
authors.initials: S
authors.lastname: Aktemur
authors.forename: Hatice Dogan
authors.initials: HD
authors.lastname: Buzoglu
authors.forename: Menemse
authors.initials: M
authors.lastname: Gümüsderelioglu
mesh_terms: D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry; D002614:Chelating Agents / Q000737:chemistry; D004492:Edetic Acid / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D012388:Root Canal Irrigants / Q000737:chemistry*; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry; D013500:Surface Tension; D013501:Surface-Active Agents / Q000737:chemistry; D013696:Temperature
chemical_list: D002593:Cetrimonium Compounds; D002614:Chelating Agents; D012388:Root Canal Irrigants; D013501:Surface-Active Agents; D012967:Sodium Dodecyl Sulfate; D004492:Edetic Acid; D000077286:Cetrimonium