Rate of formation of regular and irregular secondary dentin in monkey teeth.

An in vivo hard-tissue labeling technique was used to study the formation of regular and irregular secondary dentin in thirty-one monkey teeth. The formation of regular secondary dentin averaged 0.8 micrometer per day. No difference was found in the rate of formation of regular secondary dentin and irregular secondary dentin associated with attrition. The formation of irregular secondary dentin following restorative procedures averaged 2.9 micrometers per day. During the first 30 postoperative days less irregular secondary dentin was formed subjacent to deep cavities as compared to shallow ones. This could be the result of an initial injury to the odontoblasts caused by the operative and/or restorative procedures.