title: Vibration characteristics of dental high-speed turbines and speed-increasing handpieces.
abstract: OBJECTIVE
  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 microm 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.
authors.affiliation: The University of Birmingham, School of Dentistry, St Chad's Queensway, Birmingham B4 6NN, United Kingdom.
authors.forename: Ruth L
authors.initials: RL
authors.lastname: Poole
authors.forename: Simon C
authors.initials: SC
authors.lastname: Lea
authors.forename: John E
authors.initials: JE
authors.lastname: Dyson
authors.forename: Adrian C C
authors.initials: AC
authors.lastname: Shortall
authors.forename: A Damien
authors.initials: AD
authors.lastname: Walmsley
mesh_terms: D003754:Dental High-Speed Equipment; D004867:Equipment Design; D006801:Humans; D007834:Lasers; D008422:Materials Testing; D012399:Rotation; D013499:Surface Properties; D014732:Vibration