EVALUATION OF A NEW DEVICE FOR STERILIZING DENTAL HIGH-SPEED HANDPIECES

Dental high-speed turbines and handpieces can take up and expel microo rganisms during operation and thus need regular sterilization. This st udy established a method for validating devices used to sterilize high -speed turbines and handpieces. The air and water channels and turbine chambers were contaminated with suspensions of Streptococcus salivari us or endospores of Bacillus stearothermophilus. The effect of flushin g and/or autoclaving performed by a new device combining both procedur es was evaluated by counting the number of viable bacteria recovered f rom these devices. Further, the effect on clinically used handpieces w as evaluated. In an initial experiment, the device partially reduced S . salivarius, and the endospores survived. In a second experiment, a 5 to 6 log reduction of S. salivarius in air and water channels was obt ained. No growth was observed in clinically used high-speed handpieces , and both S. salivarius and endospores were eliminated from the turbi ne chambers. Thus, the method of validation proved capable of discrimi nating between different levels of bacterial reduction.