It has previously
been believed that enamel that is undermined by decay will collapse.
This belief is
now changing and it is believed to be due to the use of fluoride.
has reduced smooth surface caries, it has also had the unexpected effect of
strengthening the enamel thereby decreasing the possibility of collapse when
undermined by decay..
very deep dentinal caries with intact enamel.
Enamel undermined by decay. Note dark shadow under tthe enamel.
Chan, DCN: Current methods and criteria for caries diagnosis in North America. J dent edu 57 (6):422-427,
Magid, KS: Caries diagnosis: the necessity for a new standard of care. Alpha Omegan 89 (3):6-10, 1996.