Mapping cavitation activity around dental ultrasonic tips

OBJECTIVES: Cavitation arising within the water around the oscillating ultrasonic scaler tip is an area that may lead to advances in enhancing biofilm removal. The aim of this study is to map the occurrence of cavitation around scaler tips under loaded conditions. MATERIALS AND METHODS: Two designs of piezoelectric ultrasonic scaling probes were evaluated with a scanning laser vibrometer and luminol dosimetric system under loaded (100 g/200 g) and unloaded conditions. Loads were applied to the probe tips via teeth mounted in a load-measuring apparatus. RESULTS: There was a positive correlation between probe displacement amplitude and cavitation production for ultrasonic probes. The position of cavitation at the tip of each probe was greater under loaded conditions than unloaded and for the longer P probe towards the tip. CONCLUSIONS: Whilst increasing vibration displacement amplitude of ultrasonic scalers increases the occurrence of cavitation, factors such as the length of the probe influence the amount of cavitation activity generated. The application of load affects the production of cavitation at the most clinically relevant area-the tip. CLINICAL RELEVANCE: Loading and the design of ultrasonic scalers lead to maximising the occurrence of the cavitation at the tip and enhance the cleaning efficiency of the scaler.