title: Interferometric microscopy study of the surface roughness of Portland cement under the action of different irrigants.
abstract: OBJECTIVE
  Some investigations suggested common Portland cement (PC) as a substitute material for MTA for endodontic use; both MTA and PC have a similar composition. The aim of this study was to determine the surface roughness of common PC before and after the exposition to different endodontic irrigating solutions: 10% and 20% citric acid, 17% ethylenediaminetetraacetic (EDTA) and 5% sodium hypochlorite.
  
  
  METHODS
  Fifty PC samples in the form of cubes were prepared. PC was mixed with distilled water (powder/liquid ratio 3:1 by weight). The samples were immersed for one minute in 10% and 20% citric acid, 17% EDTA and 5% sodium hypochlorite. After gold coating, PC samples were examined using the New View 100 Zygo interferometric microscope. It was used to examine and register the surface roughness and the profile of two different areas of each sample. Analysis of variance (ANOVA) was carried out, and as the requirements were not met, use was made of the Kruskal-Wallis test for analysis of the results obtained, followed by contrasts using Tukey's contrast tests.
  
  
  RESULTS
  Sodium hypochlorite at a concentration of 5% significantly reduced the surface roughness of PC, while 20% citric acid significantly increased surface roughness. The other evaluated citric acid concentration (10%) slightly increased the surface roughness of PC, though statistical significance was not reached. EDTA at a concentration of 17% failed to modify PC surface roughness. Irrigation with 5% sodium hypochlorite and 20% citric acid lowered and raised the roughness values, respectively.
  
  
  CONCLUSIONS
  The surface texture of PC is modified as the result of treatment with different irrigating solutions commonly used in endodontics, depending on their chemical composition and concentration.
authors.affiliation: Investigator of the IDIBELL Institute, Campus de Bellvitge - Pavelló de Govern Feixa Llarga s/n, 08907 - L'Hospitalet de Llobregat, Barcelona, Spain, mballesterp@ub.edu.
authors.forename: Maria L
authors.initials: ML
authors.lastname: Ballester-Palacios
authors.forename: Esther M
authors.initials: EM
authors.lastname: Berástegui-Jimeno
authors.forename: Neus
authors.initials: N
authors.lastname: Parellada-Esquius
authors.forename: Carlos
authors.initials: C
authors.lastname: Canalda-Sahli
mesh_terms: D019343:Citric Acid / Q000494:pharmacology*; D003738:Dental Cements; D008422:Materials Testing; D008853:Microscopy; D012388:Root Canal Irrigants / Q000494:pharmacology*; D012973:Sodium Hypochlorite / Q000494:pharmacology*; D013499:Surface Properties / Q000187:drug effects
chemical_list: D003738:Dental Cements; D012388:Root Canal Irrigants; D019343:Citric Acid; D012973:Sodium Hypochlorite