Advances in Dental Research, Vol 3, 234-240, Copyright © 1989 by International & American Associations for Dental Research
Developmental disturbances of the rat molar induced by two diphosphonates
N. Fouda, M. Caracatsanis and L. Hammarstrom
Very few reports have been published about the effects of diphosphonates on
the cells and tissues of developing teeth. The present study was designed
to investigate possible morphological changes in ameloblasts and
odontoblasts and relate these changes to defects in the enamel surface of
erupted teeth. Young rats were injected subcutaneously with single or
multiple doses of HEDP or Cl2MDP (10 mg P/kg b.w.). Light microscopic
examination of developing maxillary first molars showed that single
injections of HEDP or Cl2MDP induced subameloblastic cysts between the
secretory ameloblasts and the developing enamel. The ameloblastic lining of
the cysts contained numerous calcified deposits. A few days after
injection, hypoplasias were seen in the enamel in areas previously occupied
by cysts. In the erupted teeth, scanning electron microscopic examination
revealed enamel hypoplasias which were mainly localized on the mesial sides
of the cusps. In addition to the previously mentioned disturbances,
multiple injections resulted in more extensive cysts, some of which
contained non-mineralized enamel matrix. Inhibition of the mineralization
of dentin and alveolar bone was also noticed.
