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

• Published in: The International journal of prosthodontics Vol. 7; no. 3; p. 234
• Main Authors: Beyerle, M P, Hensley, D M, Bradley, Jr, D V, Schwartz, R S, Hilton, T J
• Format: Journal Article
• Language: English
• Published: United States 01-05-1994
• Subjects: Alginates; Bacillus subtilis - drug effects; Bacteria - drug effects; Colony Count, Microbial; Dental Impression Materials; Disinfection - methods; Equipment Contamination; Immersion; Laboratory Infection - prevention & control; Microbial Sensitivity Tests; Mycobacterium bovis - drug effects; Pseudomonas aeruginosa - drug effects; Salmonella - drug effects; Sodium Hypochlorite - pharmacology; Spores, Bacterial - drug effects; Staphylococcus aureus - drug effects
• ISSN: 0893-2174

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.