title: Evaluation of two methods in controlling dental treatment water contamination.
abstract: Dental unit water systems are contaminated with biofilms that amplify bacterial counts in dental treatment water in excess of a million colony forming units per milliliter (cfu/ml). The Centers for Disease Control and Prevention and the American Dental Association have agreed that the maximum allowable contamination of dental treatment water not exceed 500 cfu/ml. This study was conducted to evaluate two protocols in controlling contamination of dental unit water systems and dental treatment water. Both methods used an antimicrobial self-dissolving chlorine dioxide (ClO₂) tablet at a high concentration (50 ppm) to shock the dental unit water system biofilms initially followed by periodic exposure. To treat dental treatment source water for patient care, 3 parts per million (ppm) ClO₂ in municipal/tap water was compared to use of a citrus botanical extract dissolved in municipal water. Heterotrophic microbial counts of effluent water and laser scanning confocal microscopy were performed to evaluate effects of the two treatments. Results from this study indicated that both treatments were effective in controlling biofilm contamination and reducing heterotrophic plate counts <500 cfu/ml. A comprehensive study addressing compatibility of 50 ppm ClO₂ on the metals and nonmetal components of the dental water system and effects of low-grade chemicals used on composite bonding to dentin and enamel is warranted before translation from efficacy studies to common clinical use.
  
  
  CONCLUSIONS
  This study provides evidence-based information of using two methods of controlling dental treatment water contamination. The study was conducted in a clinical practice setting in an active dental clinic and the results are meaningful to a clinician who is interested in providing safe dental treatment water for patient care.
  
  
  BACKGROUND
  Dental waterline biofilms, Dental treatment water contamination control, Chlorine dioxide, Emulsifiers, Heterotrophic plate counts, Laser scanning confocal microscopy. How to cite this article: Bansal R, Puttaiah R, Harris R, Reddy A. Evaluation of Two Methods in Controlling Dental Treatment Water Contamination. J Contemp Dent Pract 2011;12(2):73-83. Source of support: Nil Conflict of interest: None declared.
authors.affiliation: Masters Program in Public Health, University ofTexas-Houston School of Public Health,, Dallas, TX, USA.
authors.forename: Ritu
authors.initials: R
authors.lastname: Bansal
authors.forename: Raghunath
authors.initials: R
authors.lastname: Puttaiah
authors.forename: Robert
authors.initials: R
authors.lastname: Harris
authors.forename: Anil
authors.initials: A
authors.lastname: Reddy
mesh_terms: D018441:Biofilms / Q000187:drug effects; D017606:Chlorine Compounds / Q000008:administration & dosage*; D015169:Colony Count, Microbial; D019551:Dental Disinfectants / Q000008:administration & dosage*; D003748:Dental Equipment / Q000382:microbiology*; D004305:Dose-Response Relationship, Drug; D045703:Emulsifying Agents / Q000494:pharmacology*; D006801:Humans; D018613:Microscopy, Confocal; D010087:Oxides / Q000008:administration & dosage*; D014871:Water Microbiology
chemical_list: D017606:Chlorine Compounds; D019551:Dental Disinfectants; D045703:Emulsifying Agents; D010087:Oxides; C025109:chlorine dioxide