Ultrasonic descalers are used in dentistry to remove calculus and other contaminants
from teeth. One mechanism which may assist in the cleaning is cavitation generated in cooling water around the descaler. The spatial distribution
of cavitation around three designs of descaler tips and under three load conditions has been observed using sonochemiluminescence from a luminol
solution and compared with the vibratory motion of the tips in a water bath, characterised by scanning laser vibrometry. The type of cavitation was confirmed by acoustic emission analysed by a ‘Cavimeter’ supplied by NPL.
Surface profilometry and SEM of eroded hydroxyapatite pellets was performed
to quantitatively study the erosion caused by a descaler tip in both contact and non-contact modes. Densitometry was used to study the erosion
of black ink from a glass microscope slide, and determined that under the majority of conditions, no erosion was demonstrated via cavitation, by descalers operating in non-contact mode, although significant erosion was demonstrated with the tip in contact with the slide.
|Date of Award||1 Dec 2010|
|Supervisor||Gareth Price (Supervisor)|
- surface erosion