The fibrillar structure of the cemento-dentinal junction in different kinds of human teeth.

Abstract

The cemento-dentinal junction was examined in human maxillary incisors, canines and premolars by scanning electron microscopy combined with NaOH maceration. The NaOH maceration was used to remove interfibrillar substances and to observe details of the fibrillar architecture. The teeth were half-sectioned longitudinally, demineralized and macerated for 3-4 days or for 10-14 days. In the 3-4 day-macerated specimens, longitudinal sections of the cemento-dentinal junction were examined. In the 10-14 day-macerated specimens, the cementum was detached and the inner cementum surface facing the cemento-dentinal junction was examined. Observations suggested that cemental fibrils intermingle with dentinal fibrils only in places at the cemento-dentinal junction in both acellular and cellular cementum. These structural features were consistent in all kinds of teeth investigated here. Using human molars, we have previously proposed that the adhesion of proteoglycans is a main factor for the cemento-dentinal attachment and that the fibril intermingling between dentin and cementum is an accessory or secondary factor. The present study suggests that this applies to other kinds of human teeth.