Epithelially induced denticles in the pulps of recently erupted, noncarious human premolars.

Eighty-five maxillary and 90 mandibular newlyerupted, noncarious premolars from patients ages 11 to 15 were studied. All teeth were radiographed in mesiodistal and buccolingual projections to establish the presence of calcified bodies in the dental pulps. Of the premolars, 25.8% of the maxillary and 25.5% of the mandibular contained pulpal calcifications. Most were found in the radicular pulp near the apex. A slightly higher percentage of coronal calcified bodies and a significantly lower percentage of radicular calcified bodies was found in teeth whose roots were completed. Selected specimens with radiographic evidenceof calcification were sectioned serially for histological study. Two principal types of calcified bodies were found: epithelially induced denticles and pulp stones formed around amorphous cores of calcified pulp tissue. Six denticles were selected for graphic, three-dimensional reconstruction, which demonstrated that denticles are initially thimble-shaped, with the open end facing apically. Later they become complete dentin shells around a central cavity. The improper classification of true and false denticles is discussed.