Ultrasonic cleaners are a valued aid to instrument cleaning in many ge
neral dental practices. This article reviews the different ways their
cleaning efficiency has been assessed. It is recommended that burs and
files should be cleaned ultrasonically before first use. Prophylaxis
cups are not sufficiently decontaminated by ultrasonic cleaning and th
erefore should be discarded after use. Although instruments are visibl
y clean after ultrasonic cleaning and generally clean when viewed with
an electron microscope, ultrasound alone is insufficient for sterilis
ation. Further avenues of research have been highlighted.