Evaluation of the bacterial contamination of air/water syringes tips

Abstract

Effective infection control procedures to prevent cross-contamination in the dental office include care with air/water syringes. The authors had the purpose to verify the bacterial contamination of air/water syringes used in patients seen at the Restorative Dental Clinic, School of Dentistry, University of São Paulo, Brazil. Fifty disposable tips (Riskcontrol, Injecta Prod. Odontológicos) were analysed: 10, immediately after the package was opened; 10, after a single use followed by disinfection with 70% alcohol for one minute; 30, after a single use without any posterior disinfection. The samples were transported to the laboratory and, under aseptic condition, rolled and compressed on a Tryptic Soy Agar surface with 5% of defibrillated sheep blood. After a 96-hour incubation, the reading was carried out with the help of a lens. According to the manufacture’s information, the disposable tips were sterilized. In all of the tips used in patients, an uncountable amount of cfu (colony formation units) was found, revealing great contamination. In the disposable tips disinfected after being used, there was small bacterial growth, but that was incompatible with cross-contamination prevention. Therefore, we conclude that disposable air/water syringes tips must have a single use.