High Speed Imaging of Cavitation around Dental Ultrasonic Scaler Tips

PLoS One. 2016 Mar 2;11(3):e0149804. doi: 10.1371/journal.pone.0149804. eCollection 2016.

Abstract

Cavitation occurs around dental ultrasonic scalers, which are used clinically for removing dental biofilm and calculus. However it is not known if this contributes to the cleaning process. Characterisation of the cavitation around ultrasonic scalers will assist in assessing its contribution and in developing new clinical devices for removing biofilm with cavitation. The aim is to use high speed camera imaging to quantify cavitation patterns around an ultrasonic scaler. A Satelec ultrasonic scaler operating at 29 kHz with three different shaped tips has been studied at medium and high operating power using high speed imaging at 15,000, 90,000 and 250,000 frames per second. The tip displacement has been recorded using scanning laser vibrometry. Cavitation occurs at the free end of the tip and increases with power while the area and width of the cavitation cloud varies for different shaped tips. The cavitation starts at the antinodes, with little or no cavitation at the node. High speed image sequences combined with scanning laser vibrometry show individual microbubbles imploding and bubble clouds lifting and moving away from the ultrasonic scaler tip, with larger tip displacement causing more cavitation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Dental Instruments
  • Dental Scaling / methods*
  • Dental Stress Analysis / methods
  • Diagnostic Imaging / methods
  • Equipment Design / methods
  • Humans
  • Lasers
  • Ultrasonics / methods*
  • Vibration

Grants and funding

NV gratefully acknowledges financial support from the EPSRC through a studentship from the PSIBS Doctoral Training Centre (EP/F50053X/1). EP, DW, and RLS also acknowledge financial support from the EPSRC (EP/J014060/1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.