occurs regardless of the previous caries history. It
is a rapid form of decay with frank lesions seen in 3 months vs. the 18
months associated with caries development the non-irradiated patient.
After radiation therapy, saliva no
longer acts as a buffering and lubricating agent. This
loss of protection
usually provided by saliva increases susceptibility to caries.
The decay pattern in radiation caries
is different from non-irradiated teeth. Incisal
edges, cusp tips and cervical areas are the involved surfaces. The
lesion begins as diffuse demineralization that encircles the tooth and
causes it to break off at the gingival margin. Black
lesions are also common.
The change in bacterial flora, the
decrease in pH, the change in diet, and the painful inflamed oral mucosa
leading to poor oral hygiene, all add up to an increased risk of decay.
Here seen as darkened lesions in the
gingival 1/3 of the exposed clinical crown