title: Antimicrobial residual effects of irrigation regimens with maleic acid in infected root canals.
abstract: BACKGROUND
  The success of endodontic treatment depends largely on the control of microorganisms present in infected root canals. The aim of this study was to determine the residual antimicrobial activity of several final irrigation protocols with 7% maleic acid (MA) alone and combined with chlorhexidine (CHX), cetrimide (CTR) or both, in root canals infected with Enterococcus faecalis. Biofilms of E. faecalis were grown in uniradicular roots for 4 weeks. A total of 72 specimens were divided into 5 experimental groups according to the final irrigation regime used: Group 1: 2.5% NaOCl; Group 2: 7% MA; Group 3: 7% MA + 0.2% CTR; Group 4: 7% MA + 2% CHX; Group 5: 7% MA + 0.2% CTR + 2% CHX; and
  
  
  METHODS
  0.9% saline solution. Twelve roots (2/group) that were instrumented and not infected served as negative or sterility controls. The proportion of ungrown samples over 60 days was evaluated using non-parametric Kaplan-Meier survival analysis. Differences among groups were tested using the log-rank test (p< 0.05).
  
  
  RESULTS
  The association of MA with CHX and CHX + CTR as final irrigating solutions showed the best results, 5 and 4 samples out of 12, respectively, and without differences between them (p = 0.928), followed by 7% MA + 0.2% CTR with 7 out of 12. The 7% MA (11/12) group showed significant differences with respect to the groups in which MA was combined with CHX (p < 0.005) and CHX + CTR (p < 0.005).
  
  
  CONCLUSIONS
  Final irrigating solutions of 7% MA combined with 2% CHX or 2% CHX + 0.2% CTR were found to effectively improve antimicrobial root canal disinfection.
authors.affiliation: Department of Dental Pathology and Therapeutics, School of Dentistry, University of Granada, Campus de Cartuja, Colegio Máximo s/n, Granada, Spain.
authors.forename: Carmen María
authors.initials: CM
authors.lastname: Ferrer-Luque
authors.affiliation: School of Dentistry, University of Granada (Spain), Granada, Spain.
authors.forename: Silvia
authors.initials: S
authors.lastname: González-Castillo
authors.affiliation: Department of Paediatric Dentistry, School of Dentistry, University of Granada, Campus de Cartuja, Colegio Máximo s/n, Granada, Spain.
authors.forename: Matilde
authors.initials: M
authors.lastname: Ruiz-Linares
authors.affiliation: Department of Microbiology, School of Dentistry, University of Granada (Spain), Granada, Spain.
authors.forename: María Teresa
authors.initials: MT
authors.lastname: Arias-Moliz
authors.affiliation: Department of Oral Medicine, School of Dentistry, University of Granada, Campus de Cartuja, Colegio Máximo s/n, Granada, Spain.), Granada, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Rodríguez-Archilla
authors.affiliation: Department of Preventive Dentistry, School of Dentistry, University of Granada, Campus de Cartuja, Colegio Máximo s/n, Granada, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Baca
keywords: Cetrimide; Chlorhexidine; Enterococcus faecalis; Maleic acid; Residual effects