(1) Caries occurs in deciduous teeth that have hypoplastic (hypocalcified) enamel. The carious involvement is characteristic as to location and progression; commonly occurs at a very early age, often beginning very soon after the tooth has erupted; cannot be charged to local neglect, but is related very definitely to enamel deficiency. (2) At about four years of age many previously sound deciduous molars begin to develop caries on approximal surfaces; it occurs regardless of perfection of contact points. This type of caries is chargeable to environmental influence (chiefly saliva), not to local neglect (since the involved surfaces are not accessible to the tooth-brush) nor to faulty enamel formation. (3) Approximal caries in the permanent dentition typically is due to environmental influence, not to imperfect contact points, local neglect, or enamel hypoplasia. (4) In contradistinction to the above-cited three types of caries, there is susceptibility of developmental pits and fissures, especially of permanent teeth. These crevices in enamel are not related to, nor caused by, enamel hypoplasia. Caries in these locations is chargeable to local conditions (collection of food and bacteria) ; these areas are not completely cleansible with a tooth brush, and are largely beyond the influence of environmental factors.
The influence of local factors—specifically, bacterial plaque and types and numbers of bacteria—is paramount in the initiation of caries. Incidence and activity of these factors seem to depend on environmental conditions. Saliva is the most important single factor influencing tooth environment. Hence efforts to control bacterial activity in the mouth should aim first to produce saliva having the most beneficial environmental qualities. The types of caries designated in (1), (2) and (3), above, are primarily the products of faulty systemic conditions which, in turn, are dependent largely on unbalanced diets. The type of caries designated in (4), above, is due to anatomical (local) rather than to systemic fault ; the possibility of its control by dietary means is not viewed as optimistically as for the types designated above in (1), (2) and (3).Study of methods of preventing caries should proceed along dietary lines, to develop new and more specific criteria of systemic condition than have heretofore been established. Systemic condition influences composition of saliva, and saliva itself provides an index of systemic status from the oral standpoint. The preventive program of the future will probably center around regulation of diet, beginning in the prenatal period, together with prophylactic odontotomy for the care of pits and fissures as found. Prophylactic treatment and home care of the mouth will not be the main reliance, but will serve as useful and needed supplements to the procedures indicated above.
References: J. Am. Den. Assoc., 1934; N. Y. J. Den., 1938; J. Can. Den. Assoc., 1938 ; Do you want your baby to have good teeth?, 1937 (Murry and Leonie Guggenheim Dental Clinic, New York City).