There is no evidence that indicates any widespread public health problem from exposure to DUWL emissions.
7-11) Most DUWL are narrow- bore plastic tubing, which carry water to handpieces, power scalers, and 3-way (air-water) syringes.
There has been only one case reported in the dental literature suggesting a link between exposure to DUWL water containing Pseudomonas aeruginosa and localized infection in 2 immunocompromised patients.
Although there has not been evidence of a public health problem, the presence of a large number of microorganisms in DUWL emissions causes concern.
For many years, the CDC recommended flushing DUWL to reduce microbial emissions.
However, there are concerns because they have no effect on biofilms present in DUWL, often require chemical or UV treatment of filtered water, and can be expensive and may need to be replaced daily or weekly.
The quality of the water used can be better controlled and chemicals can be introduced into the DUWL to remove biofilms or retard its formation.
Manufacturing company to develop methods to control biofilms in DUWLs
Drying DUWLS overnight and on weekends by compressed air
They bypass or replace the DUWLs to provide sterile irrigants.