A light microscopy study of pulps from traumatized permanent incisors with reduced pulpal lumen

The pulps from 20 traumatized permanent maxillary incisors treated endodontically because progressive hard-tissue formation diminished the pulpal lumen, were studied with light microscopy. The tissue changes were characterized by a varied increase in collagen content. A marked increase in collagen content was associated with a marked decrease in number of cells. Areas of mineralized tissue resembling dystrophic mineralization were present in nine pulps. Osteoidlike tissue with included and lining cells was found adjacent to these mineralized areas in three pulps. In one pulp a moderate infiltration of inflammatory cells was noted, mostly lymphocytes. With the exception of the latter tooth, tissue changes in the pulps in no case warranted endodontic treatment.