THE EFFECTS OF FLUORIDE INGESTION ON THE ORGANIC MATRIX OF THE TEETH OF GROWING PIGS

¹ Department of Histology and Embryology, University of Ottawa, Ottawa, Canada, and Medical Division, Oak Ridge Institute of Nuclear Studies, Oak Ridge, Tenn.

Progressive changes have been recognized in the dentin and cementum of the teeth of pigs fed a diet containing a large dose of fluoride (1,000 ppm) for periods of 30 and 60 days.

The changes were more extensive in the incisors than in the molars. Dentin and cementum have shown a graded decrease of staining by the periodic acid-Schiff technic and toluidine blue metachromasia.

Predentin and precementum were hyperplastic, occasionally tumoral. The number of odontoblasts and cementoblasts was increased at 30 and decreased at 60 days.

The pulp cavity showed hypervascularization and decrease in stainable ground substance.

Round, clear masses, probably containing CaF₂, appeared in newly-formed dentin and cementum of fluoridized animals.

Homogeneous, compact, blue-white ash of unknown identity was detected in spodograms of demineralized sections of dentin and cementum from fluoridized animals.

The significance of these findings in relation with normal mineralization is discussed.