That the teeth and bones are similar in structure has been recognized by nearly all physiologists. Chemically they are very much alike. According to Hoppe-Seyler, the inorganic constituents are the same for bone and for dentin, about 85 per cent, calcium phosphate and from 10 to 12 per cent, calcium carbonate. The density of dentin cartilage is about equal to that of bone.
The processes of calcification are analogous. In the teeth the calcification occurs about the processes of the odontoblasts, just as in bone it occurs about the bone cells and forms lacunae. In both, the inorganic constituents are laid down in a colloidal matrix. It would therefore seem reasonable to infer that a pathologic condition which affected one might affect the other.
This, however, has not been the opinion of dentists. They believe that dental caries is a purely local affair. The present theory is that carbohydrate material