Structural changes in exposed human cementum

Frozen sections of 75 decalcified human teeth with root surfaces exposed to the oral environment during periodontal disease were examined for the presence in cementum of “pathologic granules” (Bass 1951, Benson 1963). In 72 of these teeth granule-like formations were found in exposed cementum. In only one instance were the granules also found under an unexposed root surface. A possible explanation for this exception was presented. The cemental granules do not appear to be artifacts of fixation, decalcification, or freezing. Mineralized ground sections of exposed roots did not exhibit any structural changes resembling the granules. However, upon decalcification the granules appeared. This suggests that areas from which the granules arise are filled with calcified material.