Evaluation of a hydrogen peroxide disinfectant for dental unit waterlines.
BACKGROUND
The purpose of this study was to investigate the use of a hydrogen peroxide-based dental unit waterline, or DUWL, treatment to reduce the colonization and growth of heterotrophic bacteria.


METHODS
Twenty-three dental units with self-contained water systems were randomly selected. Three of the units and tap water served as controls. Twenty-four water samples were taken at baseline and once a week for five weeks. They were serially diluted, spread-plated in duplicate onto R2A agar plates and incubated at 37 C for seven days.


RESULTS
At baseline, the tap water control had a mean count of 0 colony-forming units/milliliter, or CFU/mL, the three control DUWLs had a median count of 8,440 CFU/mL and the 20 treated DUWLs had a median count of 9,760 CFU/mL. By week 1, 19 (95 percent) of the 20 treated DUWLs had counts of less than 200 CFU/mL, and by week 4, the median count for all of the treated DUWLs was 0 CFU/mL. The measurement at week 5 showed that the reduction to below 200 CFU/mL had been maintained. Scanning electron micrographs from processed DUWL tubing samples revealed a similar pattern of results, with biofilm accumulation more evident in the untreated control specimens.


CONCLUSIONS
Following the parameters of this study, the authors used a hydrogen peroxide-based disinfectant to achieve the ADA goal of no more than 200 CFU of heterotrophic, mesophilic bacteria per milliliter of unfiltered output water.


CONCLUSIONS
An easy-to-use hydrogen peroxide-based DUWL disinfectant demonstrated effectiveness in improving the quality of water used for intraoral procedures. Protocol compliance meets the ADA year 2000 goal.
Linger
J B
JB
Department of Restorative Dentistry, University of Detroit Mercy, School of Dentistry, 8200 W. Outer Drive, Detroit, Mich. 48219-0900, USA. lingerjb@udmercy.edu
Molinari
J A
JA
Forbes
W C
WC
Farthing
C F
CF
Winget
W J
WJ
D000891:Anti-Infective Agents, Local / Q000494:pharmacology; D018441:Biofilms / Q000187:drug effects; D015169:Colony Count, Microbial; D019551:Dental Disinfectants / Q000494:pharmacology; D003748:Dental Equipment / Q000382:microbiology*; D006861:Hydrogen Peroxide / Q000494:pharmacology; D014871:Water Microbiology
D000891:Anti-Infective Agents, Local; D019551:Dental Disinfectants; D006861:Hydrogen Peroxide