Further observations on tertiary dentin in XXXX deciduous teeth.

@entity1 @entity32 @entity75 @entity1711 @entity982 @entity1710 @entity130
The structure of reparative tertiary dentin in @entity1 deciduous teeth has been studied. Reparative dentin is secreted by a new generation of odontoblast-like cells which have been subject to strong stimuli, e.g., @entity130 or deep active @entity75 with associated pulp @entity32 . Ground sections of 25 teeth were prepared, and contact microradiographs were produced. Another 30 teeth were demineralized, embedded in @entity982 , sectioned, and stained with @entity1710 and @entity1711 . Some demineralized sections from each tooth were also studied in the scanning electron microscope. Most of the teeth showed some type of tertiary dentin formation. Mineralized tissue with a varied morphology was observed. In teeth which had been subject to @entity130 , the entire pulp chamber was sometimes obliterated. Mineralization seemed to start in the incisal region, and the central part of the pulp was the last part to be obliterated. Radiolucent voids and canals were seen. The organic matrix was dense and fibrous. In the pulp chamber and especially in the root canals, resorption had often occurred, indicating that signals giving rise to odontoclasts were also present. Resorption was often followed by deposition of various amounts of cementum-like repair tissue. The cells responsible for the formation of reparative dentin are believed to be subodontoblasts or undifferentiated ectomesenchymal cells. The varied morphology of the reparative dentin, observed in the pulp of the teeth examined, indicates that different stimuli lead to induction of hard-tissue-forming cells which produce different types of hard tissue.
