Effectiveness of chlorine dioxide in disinfection on two soft denture liners.
BACKGROUND
Soft tissue denture liners frequently require replacement that necessitates complete removal from the denture base. A high speed lathe located in a "clean laboratory" is often used to facilitate removal of these materials, but it is unclear whether routine disinfection procedures reduce bacterial contamination sufficiently to prevent contamination of the laboratory.


OBJECTIVE
The first phase of this study evaluated the effectiveness of 3-minute chlorine dioxide spray and immersion disinfection procedures on 2 denture liners (Coe Soft and Coe Comfort) and stainless steel specimens used as controls. The second phase evaluated the effectiveness of spray disinfection at time intervals of 1, 3, and 10 minutes.


METHODS
Specimens made of soft denture liners attached to acrylic resin bases (10 per group) were contaminated with Escherichia coli, Staphylococcus aureus, and Candida albicans. Colony-forming units were counted after different disinfection techniques were applied. Kruskal-Wallis 1-way analysis of variance on ranks and an all pairwise multiple comparison procedures (Dunn's method) were used to test for significant differences among test groups at the P <.05 level of significance.


RESULTS
Chlorine dioxide was effective against nonporous stainless steel specimens but was inadequate for denture liners at the recommended 3-minute time of disinfection. The immersion technique was more effective than the spray technique, but the difference was not significant. Increasing the time of disinfection did not significantly reduce the numbers of microorganisms.


CONCLUSIONS
Coe Soft and Coe Comfort denture liners should be removed before entering the laboratory. These materials contain sufficient viable bacteria after routine disinfection procedures to cause contamination of the "clean laboratory."
Furukawa
K K
KK
US Army Dental Activity, West Point, NY, USA.
Niagro
F D
FD
Runyan
D A
DA
Cameron
S M
SM
D000336:Aerosols; D000704:Analysis of Variance; D002176:Candida albicans / Q000187:drug effects; D017606:Chlorine Compounds / Q000008:administration & dosage*; D019551:Dental Disinfectants / Q000008:administration & dosage*; D003822:Denture Liners / Q000382:microbiology*; D004203:Disinfection / Q000379:methods / Q000706:statistics & numerical data; D004780:Environment, Controlled; D004866:Equipment Contamination / Q000517:prevention & control*; D004926:Escherichia coli / Q000187:drug effects; D005069:Evaluation Studies as Topic; D006801:Humans; D007101:Immersion; D010087:Oxides / Q000008:administration & dosage*; D013211:Staphylococcus aureus / Q000187:drug effects; D018709:Statistics, Nonparametric; D013997:Time Factors
D000336:Aerosols; D017606:Chlorine Compounds; D019551:Dental Disinfectants; D010087:Oxides; C025109:chlorine dioxide