Natural and induced radiation caries: A SEM study.

Radiation caries is a well-known indirect side effect of head and neck radiotherapy. The initiation and progression of radiation caries were studied using an in situ model. The morphology of induced carious lesions was compared with that of natural radiation caries. Both natural and induced radiation caries showed the same patterns of decay; widespread areas with porosity of enamel, crater formation with exposure of subsurface enamel, preferential dissolution of prisms with hollowing out of prism cores, loss of large parts of surface enamel and loss of full enamel coverage exposing the underlying dentin. In irradiated patients most enamel slabs were severely demineralized within 6 weeks whereas in control subject the slabs showed no significant demineralization after 12 weeks. The model may offer an excellent opportunity to study preventive fluoride regimens because of the rapid induction of radiation caries and its similarity with natural lesions.