How Your Dentist Diagnoses Tooth Decay Although any tooth
surface is susceptible to decay, the most vulnerable spots are
the uneven or hard-to-reach areas where bacteria can take
refuge. Particularly prone to decay are the crevices (known as
pits and fissures) on the surface of the crown, the points where
adjacent teeth meet, and the exposed neck of the tooth at the
gum line. Root decay is a growing problem, particularly among
people older than age 55 whose gums have receded as a result of
periodontal disease. Your dentist can often spot decay on the
visible surfaces of the teeth, while cavities in unseen
spots—such as in the pits and fissures or between
teeth—generally show up as dark areas on X-rays. A traditional
method of uncovering decay by probing for soft spots in the
teeth with a sharp metal tool has fallen out of favor.
Researchers began to suspect that this practice actually
augmented the decay process by piercing areas of soft enamel and
spreading bacteria from one tooth to another. Still, finding