S. Zammitti et al., USE OF ENVIRONMENTAL SCANNING ELECTRON-MICROSCOPY TO EVALUATE DENTAL STAIN REMOVAL, The Journal of clinical dentistry, 8(1), 1997, pp. 20-25
The purpose of the study was to assess the usefulness of environmental
scanning electron microscopy (ESEM) to evaluate stain removal from ex
tracted teeth. The ESEM differs from conventional SEM in that no sampl
e preparation is needed, eliminating artifactual changes. Furthermore,
the same sample can be viewed on multiple occasions, allowing ''befor
e'' and ''after'' pictures of the same tooth. As a model stain removal
device, we tested the Sonicare(R) sonic toothbrush, which has previou
sly been shown to remove dental stain in vivo. Twelve freshly extracte
d teeth with extrinsic coffee, tea or tobacco stain were obtained for
the study. Nine of these had heavy stain (stain covering more than one
-third buccal or lingual surface) and were used without further modifi
cation. Three teeth were treated in vitro with chlorhexidine and a mix
ture of coffee and tea to enhance staining. All teeth were examined by
ESEM at three times: prior to brushing, after 15-30 seconds of brushi
ng, and after 60-80 seconds of brushing. Light microscopy and 35 mm ph
otography was also done to correlate the ultrastructural changes with
those visible at low magnification. Water, mouthwash and 30% slurry of
toothpaste were used as fluid vehicles during brushing, but little di
fference in stain removal was noted among these three fluids. Approxim
ately half the stain was removed within 15-30 seconds, and most visibl
e stain was removed in 60-80 seconds of brushing. Pits and crevices of
tooth enamel that were smaller than the bristle diameter, and thus wo
uld be inaccessible to abrasive cleaning by direct bristle contact, we
re generally found to be stain-free. These findings confirm previous r
eports of the stain removal effectiveness of the Sonicare, and demonst
rate the usefulness of ESEM for stain removal studies.