Summary of factors in the etiology of caries : (1) Exciting factors—food debris, bacteria, acids. (2) Local predisposing factors—dietary : sugars and other carbohydrates ; lack of type and kind of food for proper (a) mouth function, (b) mouth prophylaxis, (c) environment. Structural defects ; anatomic relationships, and form and shape, of teeth. (3) Systemic predisposing factors—heredity; diet, endocrine influence, and systemic disturbances during period of formation of teeth. (4) Possible factors not yet proven—vitamins, calcium, phosphorus, diet, and systemic disturbances, as related to health of bone and soft tissue, and affecting mouth environment; buffer and pH values of saliva; role of dental pulp affecting susceptibility of dentin.
Caries appears to be due to a number of related conditions, not to a single factor—to exciting causes and to predisposing causes. Whether B. acidophilus is the sole bacterial exciting factor, or present owing to changed environment favorable to caries, is uncertain. Structural defects in teeth predispose to caries. Shape and position of teeth, and shape of the dental arch, favor susceptibility, if there is lack of function, or tendency to retention of food or debris. Any type of diet that favors lodgment of food particles and bacteria on teeth, and ensuing local acid formation—resisting natural and artificial means of mouth hygiene—induces caries. Regulation of diet in susceptible individuals seems to increase resistance, possibly owing to ensuing improvement of local conditions. Low consumptions of cane-sugar and of refined cereal appear to aid control of caries. A diet favoring normal mastication increases resistance to caries. Unbalanced diet, vitamin deficiency, endocrine influence, and systemic disturbance—during the period of formation of teeth—may cause structural dental defects and susceptibility to caries. Vitamins A, B, C, and D indirectly influence mineral levels in the body and, when adequate, keep bone and soft tissues in healthy condition. Calcium and phosphorus in the diet, and systemic diseases, affect the health of bone and soft tissues, which may influence oral conditions. Unhealthy systemic conditions tend to change the mouth environment. The author has not observed any favorable results on the progress of caries from changes in diet, including additions of calcium, phosphorus and vitamins. The buffer and pH values of saliva, as affecting susceptibility to caries, may be influential factors. This is also true of the role of dental pulp as affecting susceptibility of dentin. Heredity is a more definite factor in the etiology of caries than is generally accepted. Related physical characteristics and susceptibilities to caries have been traced through many families. The author believes, contrary to current views, that caries occurs at all ages; periodontal disease is quite prevalent during early years; and active caries and periodental disease frequently occur together in the same mouth.
Reference: Diseases of the mouth, 4th ed., 1938 (C. V. Mosby Company, St. Louis).