Performance of high-speed dental handpieces - Subjected to simulated clinical use and sterilization

Background. The authors investigated the performance of nine commercially available highspeed air-turbine dental handpieces subjected to 1,000 simulated clinical uses and sterilizations. Methods. Six new handpieces from each of nine different models were subjected to simulated clinical use with a custom-made handpiece wear tester and then autoclaved. Ten parameters related to clinical performance (longevity, power, turbine speed, fiberoptic transmission, eccentricity, noise, chuck performance, visibility angle, interocclusal clearance and water coolant spray pattern) were measured at baseline and after 250, 500, 750 and 1,000 use/sterilization cycles. Results. Power, turbine speed, eccentricity and noise performance were statistically analyzed using one-way analysis of variance and Tukey post hoc pairwise comparison tests at the .05 significance level. At baseline, significant differences were found between models for all of these parameters. In general, from baseline to 1,000 cycles, the handpieces exhibited greater eccentricity and reduced fiberoptic performance. Longevity data analyzed by using Geban's generalized Wilcoxon test for comparison of survival distributions (alpha=.05) revealed significant differences between the handpiece models. Conclusions. The results of this study indicate that no handpiece model is superior to the others in all parameters evaluated. All models evaluated can be expected to perform for at least 500 clinical use/sterilizations, or approximately one year, if properly maintained. Clinical Implications. Clinicians need to be able to identify handpieces that can withstand repeated heat sterilization without loss of performance or longevity. The results of this study will aid clinicians in selecting handpiece models that meet their needs.