Changes
in Dental Enamel
Yasuo MIAKE, Masaya OGIWARA
and Takaaki YANAGISAWA
Department of
Ultrastructural Science,
In
the present study, the effects of two commercial bleaching agents; Hi-Lite
(Hi-L) and Nite White Excel (NWE), on enamel were investigated by observations
with CMR, SEM, XRD and HR-TEM, focusing on the effects on enamel crystals. CMR and
XRD showed no change in degree of mineralization and crystallinity after
bleaching. On SEM, gaps along the prism sheath and cracks between crystals were
observed on the enamel surface of Hi-L-bleached and NWE-bleached enamel. On
HR-TEM, crystal growth findings were observed in some regions of Hi-L-bleached
enamel, while crystal demineralization findings were observed in NWE-bleached
enamel. All the above changes were limited to the very superficial layer of
enamel in all the samples.