Resistance to disinfection of a polymicrobial association contaminating the surface of elastomeric dental impressions.
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.
Giammanco
Giovanni M
GM
Department of Health Promotion Sciences, Section of Microbiology, University of Palermo, Italy. g.m.giammanco@unipa.it
Melilli
Dario
D
Rallo
Antonio
A
Pecorella
Sonia
S
Mammina
Caterina
C
Pizzo
Giuseppe
G
D018441:Biofilms / Q000187:drug effects*; D002176:Candida albicans / Q000187:drug effects / Q000502:physiology; D015169:Colony Count, Microbial; D019551:Dental Disinfectants / Q000494:pharmacology; D003760:Dental Impression Materials; D004203:Disinfection / Q000379:methods*; D004866:Equipment Contamination; D005976:Glutaral / Q000494:pharmacology*; D008422:Materials Testing; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000502:physiology; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology*; D012117:Resins, Synthetic; D012826:Silicone Elastomers; D013211:Staphylococcus aureus / Q000187:drug effects / Q000502:physiology
D019551:Dental Disinfectants; D003760:Dental Impression Materials; C022821:Impregum; D000644:Quaternary Ammonium Compounds; D012117:Resins, Synthetic; D012826:Silicone Elastomers; D005976:Glutaral