Effective cleaning and decontamination of the internal air and water channels, heads and head-gears of multiple contra-angle dental handpieces using an enzymatic detergent and automated washer-disinfection in a dental hospital setting

Dental handpieces (DHPs) are reusable invasive medical devices that must be cleaned, decontaminated, lubricated and steam sterilized after use. DHPs have a complex internal design including narrow channels, contamination of which can compromise sterilization. DHPs are not designed for routine disassembly, making cleaning/decontamination efficacy difficult to monitor. Washer-disinfection is the preferred method of decontaminating DHPs, but few studies have investigated its direct effectiveness at reducing microbial contamination internally.To use contra-angle DHPs as a model system to investigate the effectiveness of washer-disinfection at reducing microbial contamination of internal components of multiple DHPs.The air and water channels and heads of 10 disassembled contra-angle DHPs (BienAir, Biel/Bienne, Switzerland) were inoculated separately with 10On average, an approximate 5 log or greater reduction in microbial cfu and a93% reduction in protein from DHP heads and channels was consistently recorded following washer-disinfection for all DHPs under all conditions tested.The internal components of multiple DHPs can be effectively cleaned and decontaminated by washer-disinfection.