I'm not sure what this is.  You can get abnormal calcifications on the teeth
from too much fluoride.  Most likely this is a problem with the enamel, but
it is not likely due to breastfeeding.  Even if it were, these are baby
teeth, and will be replaced by adult teeth starting around 6 years.  There
is no reason to believe that nursing would cause problems for the adult
teeth.  (No matter what the dentist told this mother).

Jack Newman, MD, FRCPC