Immersion disinfection of irreversible hydrocolloid impressions with sodium hypochlorite. Part I: Microbiology

Marcus P. Beyerle, Donna M. Hensley, Donald V. Bradley, Richard S. Schwartz, Thomas J. Hilton

Research output: Contribution to journalArticle

24 Scopus citations


Current American Dental Association infection control guidelines recommend immersion disinfection of irreversible hydrocolloid impressions, and this study further defines the parameters for use of sodium hypochlorite. Sodium hypochlorite has been shown to be an effective disinfectant for impressions; however, it has not been fully evaluated for optimum immersion time and concentration, in this study, irreversible hydrocolloid impressions contaminated with different bacteria were immersed in varying concentrations of sodium hypochlorite for 1, 5, or 10 minutes. Dilute solutions of sodium hypochlorite (0.525% or 0.0525%) produced a 4-log10 (99.99%) reduction in colony-forming units of Staphylococcus aureus, Salmonella choleraesuis, or Pseudomonas aeruginosa after 1 to 5 minutes’ immersion. Full-strength sodium hypochlorite (5.25%) required 5 minutes to produce a 4-log10 reduction of Bacillus subtilis. A 4-log10 reduction of Mycobacterium bovis was not obtained under any conditions examined.

Original languageEnglish (US)
Pages (from-to)234-238
Number of pages5
JournalInternational Journal of Prosthodontics
Issue number3
StatePublished - Jan 1 1994


ASJC Scopus subject areas

  • Oral Surgery

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