Resistance to disinfection of a polymicrobial association contaminating the surface of elastomeric dental impressions

New Microbiol. 2009 Apr;32(2):167-72.

Abstract

The aim of this study was to evaluate the ability to resist disinfection of a polymicrobial association contaminating the surface of dental impressions obtained with two different elastomers: a polyether (Impregum) and an addition-polymerized silicone (Elite). Impressions were contaminated with a mixture of three biofilm-forming microorganisms (Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans) and disinfected immediately after contamination, or after microbial layers were allowed to develop during a six-hour storage. Two commercial disinfectants were tested: MD 520 containing 0.5% glutaraldehyde and Sterigum Powder without glutaraldehyde. Residual contamination was recovered by mechanical rinsing immediately after disinfection and after a six-hour storage of disinfected impressions, and assessed by colony counting. Both disinfectants tested were shown to be effective in reducing the microbial presence on the impression materials, achieving at least a 102 reduction of microbial counts compared to water rinsing. However, Sterigum was generally less effective on the Elite elastomer and could not grant disinfection on six-hour aged P. aeruginosa and C. albicans microbial layers. The results of this study suggest that the materials used for the impressions influence the efficacy of disinfection. Disinfectants should be tested according to conditions encountered in everyday clinical practice and the need for immediate disinfection of impressions should be clearly indicated by manufacturers.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biofilms / drug effects*
  • Candida albicans / drug effects
  • Candida albicans / physiology
  • Colony Count, Microbial
  • Dental Disinfectants / pharmacology
  • Dental Impression Materials*
  • Disinfection / methods*
  • Equipment Contamination*
  • Glutaral / pharmacology*
  • Materials Testing
  • Pseudomonas aeruginosa / drug effects
  • Pseudomonas aeruginosa / physiology
  • Quaternary Ammonium Compounds / pharmacology*
  • Resins, Synthetic
  • Silicone Elastomers
  • Staphylococcus aureus / drug effects
  • Staphylococcus aureus / physiology

Substances

  • Dental Disinfectants
  • Dental Impression Materials
  • Impregum
  • Quaternary Ammonium Compounds
  • Resins, Synthetic
  • Silicone Elastomers
  • Glutaral