title: Evaluation of antimicrobial effectiveness and dentine mechanical properties after use of chemical and natural auxiliary irrigants.
abstract: OBJECTIVE
  To evaluate the effect of GSE, NaOCl, CHX and QMix as an antimicrobial agents against Enterococcus faecalis and their influence on flexural and ultimate tensile strength of root canal dentine.
  
  
  METHODS
  Root canals were divided into five groups (n=10) according to the substances used: 2.5% NaOCl, 2% CHX, 6.5% GSE, Qmix and control group (distilled water) (DW). Final irrigation was done with 17% EDTA in all groups, except when DW was used. The number of colony-forming units was used to evaluate the antimicrobial activity. Dentine beams were used to assess the flexural strength after treatment with substances as described before (n=10). The UTS was evaluated after the treatment of root dentine hourglass shape sections with the same substances (n=30).
  
  
  RESULTS
  The lowest bacteria contamination was observed for CHX and GSE, while NaOCl and QMix showed an intermediate antimicrobial activity (p>0.05). NaOCl and QMix significantly reduced the mechanical properties of dentine (flexural strength and UTS) (p<0.05) and no statistical difference was found among CHX, GSE and DW (p>0.05).
  
  
  CONCLUSIONS
  CHX and GSE were more effective than NaOCl and QMix against E. faecalis. Furthermore, they did not harm dentine mechanical properties as observed for NaOCl and QMix.
  
  
  CONCLUSIONS
  The use of GSE can be recommended for endodontic procedures since it has good antimicrobial activity and does not interfere in the mechanical properties of dentine; similarly to CHX.
authors: Department of Restorative Dentistry, Dental School of Universidade de Passo Fundo, Passo Fundo, RS, Brazil; Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, Chicago, IL, USA. Electronic address: dgscecchin@yahoo.com.br.
authors: Doglas
authors: D
authors: Cecchin
authors: Department of Restorative Dentistry, Dental School of Universidade de Passo Fundo, Passo Fundo, RS, Brazil; Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, Chicago, IL, USA.
authors: Ana Paula
authors: AP
authors: Farina
authors: Department of Restorative Dentistry, Dental School of Universidade de Passo Fundo, Passo Fundo, RS, Brazil.
authors: Matheus Albino
authors: MA
authors: Souza
authors: Department of Restorative Dentistry, Dental School of Universidade de Passo Fundo, Passo Fundo, RS, Brazil.
authors: Lourenço Luís
authors: LL
authors: Albarello
authors: Department of Restorative Dentistry, Dental School of Universidade de Passo Fundo, Passo Fundo, RS, Brazil.
authors: Alicia Pamela
authors: AP
authors: Schneider
authors: Department of Restorative Dentistry, Dental School of Universidade de Passo Fundo, Passo Fundo, RS, Brazil; Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, Chicago, IL, USA.
authors: Cristina Mattos Pimenta
authors: CM
authors: Vidal
authors: Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, Chicago, IL, USA.
authors: Ana Karina
authors: AK
authors: Bedran-Russo
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D003786:Dental Pulp Cavity / Q000187:drug effects; D003804:Dentin / Q000187:drug effects*; D013293:Enterococcus faecalis / Q000187:drug effects*; D006801:Humans; D055595:Mechanical Phenomena / Q000187:drug effects; D008963:Molar / Q000187:drug effects; D011897:Random Allocation; D012388:Root Canal Irrigants / Q000494:pharmacology*; D016369:Smear Layer / Q000737:chemistry
chemical_list: D000890:Anti-Infective Agents; D012388:Root Canal Irrigants
keywords: Disinfection; Endodontic irrigation; Flexural strength; Ultimate tensile strength