VARIATIONS IN THE LESIONS AND ACTIVITY OF DENTAL CARIES

¹ Laboratory of Oral Histology, School of Oral and Dental Surgery, Columbia University, New York, N. Y.

The clinically observed variations in the activity of dental caries seem to be related to these three factors:

(1) Systemic conditions. A disturbance of some phase of the calcium-phosphorus-vitamin D complex appears to increase the activity of dental caries.

(2) Character and location of the lesions. The lesions of dental caries can be divided into three groups: (a) acute dental crown caries, (b) chronic dental caries, and (c) acute dental root caries according to their form, location on the teeth and their different activity.

(3) Change in the permeability of the teeth. The comparatively high permeability of recently erupted teeth allows the external destructive force (acid) to penetrate rapidly, resulting in acute dental caries. On the other hand, the lowered permeability of matured teeth is a barrier to this attacking force; hence the slower penetration of the chronic type of the lesion.

The fact that there exists a variation in the activity of acute dental crown caries and chronic dental caries, suggests that the teeth offer a varying resistance to external attack.