快猫短视频

ORAL water sprays used by dentists contain levels of some bacteria that could
kill vulnerable patients, government researchers have discovered.

They found that levels of opportunistic pathogens exceeded EU drinking water
safety limits in 52 out of 55 water samples taken from 21 dental surgeries in
the south-west of England.

This means people with weakened immune systems, such as cancer patients and
those with HIV infection, are at risk, the researchers warn. James Walker of the
Centre for Applied Microbiology and Research at Porton Down and his team found
several types of opportunistic pathogens in many of the dental unit water lines
(DUWs) tested, including species of Mycobacterium and Legionella
鈥攂oth of which can cause life-threatening pneumonia.

David Turner of the British Dental Association (BDA) admitted to New
快猫短视频: 鈥淧eople with compromised immune systems should worry.鈥�

The researchers also isolated oral streptoccoci in 10 per cent of the
samples. Since the bacteria is only found in the mouth, it is most likely that
during dental procedures it was sucked back into the tools and into the DUW.
Robert Staat of the University of Louisville鈥檚 school of dentistry has also
found oral streptococci in DUWs. 鈥淭his is like sharing spit,鈥� he says.

Normally, most of the bacteria breeding in DUWs occur naturally in the
environment and pose little threat to most people. Even so, healthy patients
shouldn鈥檛 be exposed to these levels of bacteria when they are at a healthcare
facility, argues Hugh Pennington, a microbiologist at the University of
Aberdeen. 鈥淚 wouldn鈥檛 want to have these in my mouth.鈥�

Walker鈥檚 team found levels of bacteria between 5 and 1200 times higher than
the permitted 2500 microbes per teaspoon of water. Some of the highest bacterial
counts came from DUWs that were either supplied with bottled water or were
recently sanitised. This casts doubt on the effectiveness of recommendations by
the BDA and its US counterpart, the American Dental Association (ADA) that
surgeries should use bottled water and disinfectants to reduce the risk from
bacteria.

The ADA told 快猫短视频 that similar studies carried out in
several US cities revealed bacterial counts that surpass its own safety
guidelines.

Dentists in both the US and Britain are advised to use sterile water for
immune compromised patients and those receiving surgery where the gum line is
cut. But both the ADA and BDA admit it鈥檚 not clear how strictly this advice is
followed.

Despite the millions of people who visit a dentist each year, contaminated
dental water was blamed for only a handful of infections. Although some patients
died, the link to dental water was never proved.