Vibration characteristics of dental high-speed turbines and speed-increasing handpieces

Objectives Vibrations of dental handpieces may contribute to symptoms of hand-arm vibration syndrome in dental personnel and iatrogenic enamel cracking in teeth. However, methods for measuring dental handpiece vibrations have previously been limited and information about vibration characteristics is sparse. This preliminary study aimed to use a novel approach to assess the vibrations of unloaded high-speed handpieces in vitro. Methods Maximum vibration displacement amplitudes of five air turbines and two speed-increasing handpieces were recorded whilst they were operated with and without a rotary cutting instrument (RCI) using a scanning laser vibrometer (SLV). Results RCI rotation speeds, calculated from frequency peaks, were consistent with expected values. ANOVA statistical analysis indicated significant differences in vibrations between handpiece models (p < 0.01), although post hoc tests revealed that differences between most individual models were not significant (p > 0.11). Operating handpieces with a RCI resulted in greater vibrations than with no RCI (p < 0.01). Points on the head of the handpiece showed greater vibration displacement amplitudes than points along the body (p < 0.01). Conclusions Although no single measurement exceeded 4 μm for the handpieces in the current test setup (implying that these vibrations may be unlikely to cause adverse effects), this study has formed the basis for future work which will include handpiece vibration measurements whilst cutting under clinically representative loads.