None of the three disinfectants recommended by dental unit manufacturers were completely effective on dental office water lines, according to a study in Water Research.
Researchers in France tested three disinfectants — Calbenium, Oxygenal 6 and Sterispray — on bacterial biofilms to see how well they reduce biofilm formation and eradicate already formed biofilms in dental water lines. The disinfectants were tested against bacteria, fungus and an amoeba.
Calbenium was the most effective of the three disinfectants, but it did not kill the amoeba.
"Unfortunately, our results showed that none of the three disinfectants commonly used are completely effective," Damien Costa, lead author of the study, said in an Elsevier report. "What is most worrying is that none of the disinfectants could kill the amoeba, which means they are still dangerous to patients and dentists even after water lines have been sterilized."
There have been some instances of patients becoming infected from contaminated dental lines. Elsevier cited an incident where a woman was diagnosed with Legionnaire's disease after a visit to a dentist. She was hospitalized and later died.