Factors in the Cause and Prevention of Dental Caries (Part I)

By S. M. WENGER and R. L. HOESLY of The Wisconsin Alumni Research Foundation

A dentist once remarked that he experienced a most gratifying feeling after cleaning a perfect set of teeth, the only one he encountered in his many years in the practice of dentistry.

He was one of the comparatively few dentists who has ever had that privilege. It is not because people with perfect sets of teeth don’t need the services of a dentist but because there are so few people, particularly in the United States, possessing perfect sets of teeth.

It has been estimated that there are eight hundred million (800,000,-000) carious teeth (active and restored) in this country. There are 126,000,000 people. In other words there is an average of 6.3 carious teeth per person, which is almost 1/5 of each set.

In the early history of the dental profession, it was the general consensus of experts that dentistry was the practice of repairing the inevitable and unpreventable decaying of teeth.

Today, however, a new attitude is apparent. Dentistry is experiencing a revolutionary change from a reparative science to a preventive science.

But what of the cause of these 800,000,000 carious teeth and how to prevent decay?

There is naturally much disagreement as much to the factors which actually cause dental decay. There are various school of thought, each of which contributes definite and authoritative evidence to substantiate the theories advanced. Each school contributes a theory and several appear to prove conclusively that there are a number of accessory factors.

A recognition of these integral factors is the starting point for effecting the prevention of dental caries.

Kugelmass has very conveniently divided the caries producing factors in to five groups:

  1. Constitutional Factors
  2. Endocrine Factors
  3. Metabolic Factors
  4. Nutritional Factors
  5. Oral Factors

Constitutional or Environmental Factors

Probably the predominant of the constitutional or environmental factors is familial susceptibility. Kugelmass found that 7 out of 100 children with dental caries had a familial susceptibility to the disease. He also observed that 9 out of 100 children who were free from caries had an immunity to the disease. Six of these 9 children came from families with dental caries despite the prevalence of the disease in other members of the family.

Family and chemically, there is a marked difference in the dental structure which a child inherits. Kugelmass also found in his study that the cusp-inclines are steeper in the caries-susceptible group and that members of the same family are less susceptible to dental caries because of a different dental structure with less steep cusp-inclines and fewer food impacting areas.

Bunting showed that heredity is responsible for caries susceptibility when he showed that caries-free children could eat any kinds of foods and any quantities of sugar without increasing caries or the B. acidophilus of the mouth. Jay also found that children immune to dental caries through heredity could eat any amount of sugar and remain free from lactobacilli.

Experimental work done by Boyd, Zentmire and Drain on 45 children under strict dietary control indicated that Bacillus acidophilus and other organisms of equivalently high acid producing power may exist in large numbers in mouth consistently free from active caries, and pointed out that no available facts demonstrate that bacteria can of themselves induce caries in teeth of individuals whose diet is adequate.

On the other hand Johnston and coworkers found among a group of 9 children, exhibiting progressive caries, that lactobacillus acidophilus was present continuously in 5 of the 9 cases while in the 27 cases with non-progressive caries, lactobacillus acidophilus was continuously absent in 18 out of the 27.

Since the teeth of infants begin to develop about six weeks after conception and incidentally continue for about twenty years, the prenatal factor is being given increased attention. Toverud and Toverud demonstrated that a balanced maternal diet was exceedingly valuable for the teeth of the infant.

J. B. Stone points out the importance of an adequate diet for the pregnant woman not merely for her own health, but also to provide her child with sound bones and teeth.

Because pre-natal care in building sound strong teeth and bones is one of the newest and most widely discussed subjects, it will be dealt with separately in another of this series

Internal Secretions or The Endocrine Factors

In observing chronic caries in children with endocrine disturbances, Kugelmass found six with hypothyroidism, two with hyperthyroidism, two with hypopituitarism and one with hyperparathyroidism. Upon establishing a basal equilibrium with the determining endocrine condition under control, caries w as arrested –provided of course the children were maintained on optimal diets.

Hogeboom also lists these four endocrine disturbances together with resulting dental symptoms in s study of endocrine disturbance and ‘teen age caries. He feels that endocrinology, after all, is just a part of physiology, and that if the problem of dental caries is ever to be solved, the nutritionist will need to consider the effects of the internal secretions in a study of the problem and co-relate his findings with those of the clinician.

Metabolic Factors

It is the opinion of Boyd, Drain and Stearns that no factor contributing to the adequacy of metabolism, whether it be of exogenous or endogenous origin, can be ignored in evaluating the causes of dental caries. They maintain that it is evident that considerable individual variation exists in the efficiency of utilization of similar diets.

On comprehensive observations of over 100 children they concluded that a close correlation exists between the metabolic efficiency of the organism as a whole and the resistance of the tooth to decay.

Twelve per cent of 100 caries-susceptible children examined by Kugelmass had metabolic disorders such as cyclic vomiting, celiac and chronic sinusitis. In Kugelmass cases tooth decay was not arrested until the metabolic conditions were alleviated and he concluded that “That which is absorbed and utilized rather than that which is offered, is significant in resistance to decay”.

Nutritional or Dietary Factors

Undoubtedly the most widely discussed factor in the prevention of caries is the nutritional or dietary factor.

The diet theory has various schools of thought. One school represented by Drain and Boyd and also by Hanke feel that adequate diets are the main factor because they improve the general resistance of the body.

Mellanby believes however that erupted teeth are very similar to bone in many respects and that caries prevention is dependent upon the provision of conditions suitable for normal calcium and phosphorus metabolism.

The work of a third school, Howe and Hanke, places considerable emphasis on the regular intakes of large amounts of Vitamin C.

In contrast, there are of course many theories which stress the importance of other factors rather than those of diet. These have been discussed under the various other headings.

In 1934 a panel discussion made up of the advocates of these various dietary theories agreed that all of the theories discussed could be absorbed by the ideas proposed by Boyd and Drain-i.e. an adequate diet.

Naturally that brings up the question as to what constitutes an adequate diet.

According to McCollum there was no less than 37 individual food elements which should be supplied in adequate amounts in order to develop and maintain optimal health. These consist of 18 amino acids supplied by the protein, carbohydrates for energy, 1 fatty acid, 11 minerals and at least 6 vitamins.

Obtaining proper amounts of carbohydrates, fats and proteins does not afford much difficulty.

The vitamins and the minerals, both of which are very important in building strong bones and sound teeth are in many instances the lacking elements in diets.

When a diet deficient in Vitamin A was fed by Mellanby and King to experimental animals, a degeneration of the dental nerves was noted. Fortunately, however, Vitamin A is adequately supplied in most diets because it is found in eggs, butter, milk, vegetables, meats and fruits.

Vitamin C free diets resulted in changes in the pulp and dentin, according to Rosebury. Hanke and Harris found that deficiency in Vitamin C is a contributing cause of dental caries and Kugelmass found that 24 of his caries-susceptible children showed a diminished intake of Vitamin C while 47 caries-immune children apparently ingested excessive amounts of Vitamin C.

Calcium and phosphorus are the principal minerals required for the building of bones and teeth. Therefore, it is interesting to note Mrs. Mellanby’s study in which she concludes that “since teeth as well as bones are largely built up of calcium and phosphorus, it is essential, especially in the developing animal, that the diet contain a certain supply of these substances. The amount necessary for a perfect calcification can, however, in the presence of abundant Vitamin D be brought to a low level, while the large supply in the food will not be utilized unless Vitamin D is present.

Kugelmass also found that in most cases of children with low calcium intake, the problem was more of increasing the absorption of calcium than of increasing the total calcium intake.

Studiest seem to indicate quite definitely that the minerals, calcium and phosphorus together with Vitamin D, their assimilating agent, are three of the most important constituents of an adequat e diet for preventing dental caries. Results of a study n 162 children, ages 2-17, revealed that the group receiving extra Vitamin D, their assimilating agent, are three of the most important constituents of an adequate diet for preventing dental caries. Results of a study on 162 children, ages 2-17, revealed that the group receiving extra Vitamin D had less than half as many cavities as the group without this necessary food factor.

In the report of a four year dental survey by Hawkins, it was demonstrated that the acid-base balance and the calcium phosphorus balance and the calcium phosphorus balance with Vitamin D were found to be the principal factors in the production or absence of caries.

Fortunately all except one of the necessary constituents of an adequate diet are quite readily available if foods are selected in the correct proportions. Vitamin D is this one element. Dental caries can often be attributed, as has been shown above, to a deficiency of this Vitamin in the average diet. However, the extreme scarcity of Vitamin D in foods is a nutritional problem in itself and will be discussed further in another article of this series.

Oral Hygiene Factors

Oral hygiene is of course of considerable importance in controlling dental caries. It removes food particles and thus reduces fermentation which otherwise may cause decay.

It has been assumed that primitive people who had no idea what a tooth brush looked like kept their teeth sound by eating coarse hard food.

However this assumption loses some of its value in the fact that fossil remains indicate extremely worn teeth with evidences of caries and abscesses. It is reasonable to assume that primitive man undoubtedly suffered extreme pain and much discomfort from his teeth.

In this connection Klein and McCollum found that coarse particles, lodged in the crevices of the teeth caused more fermentation than a finely pulverized diet which was easily washed away by the saliva. The chewing of coarse hard foods does however play an important part as a masticatory stimulation because it massages the gums and teeth.

It has been noted by Schnak that Hawaiian poi, a highly fermentable carbohydrate foodstuff, causes little dental caries in Hawaiian children because it is cohesive in the mouth and does not cling to the teeth.

Although oral hygiene is a primary factor it is only one of several. Tisdall says, “We can recommend the brushing of the teeth and the cleansing of the mouth as an aid in the prevention of tooth decay, but no brushing can remove all the food debris and bacteria from all the surfaces of the teeth”.

Bricker states that the oral cavity is the seat of more focal infection than any other part of the body. For this reason patients are made to realize the relative importance of well-brushed teeth and a clean mouth.

The father of Medicine, Hippocrates made the significant statement that disease must be combated at its source. Medicine has always sought to combat disease at its source; modern Dentistry proceeds in like manner in the prevention of dental caries.

Brekhus and Armstrong ably stated the new trend in dentistry when they said, “From clinical experience and close observation, it became evident to the practicing dentist that the ‘clean tooth’ theory did not fulfill all its promises and it was not long before doubts were expressed that this theory embodied the whole truth and nothing but the truth; and the researchers marched on.”



1McCollum, E.V., Diet Does It, McCall’s

March 1934.

2Kugelmass, I. Newton, Dental Caries in

Children, N. Y. State Jrl. of Medicine, 37:20,

1733-1742, October 15, 1937.

3Ibid. p. 1733.


5Bunting, R. W., J. Dent. Research,

14:93, 1934

6Jay, Journal of Pediatrics, 8:733, 1936.

7Boyd, J. D., Zentmire, Z., Drain, C. L.,

Bacteriological Studies in Dental

Caries., Jrl. of Dental Research,

13:6, 443-452, Dec. 1933.

8Johnston, M. M. and other, Lactobacillus

Acidophilus in Dental Caries, J.

  1. A. Dent. A., 23:1493-1497, August


9Orban, B., Dental Histology and Em-

bryology, p. 175, 1929.

10Bodecker, C. F., Dental Histology and

Embryology, p. 110, 1926.

11Toverud and Toverud, Int. J. Orthod.

19:91, 1933.

12Stone, J.B., Children’s Teeth in Rela-

tion to Pediatric Practise, South.

Med. Journal, 29:731, July 1936.

13Kugelmass, I. Newton, Dental Caries

in Children, N.Y. St. Jrl. of Med.,

37:20, 1734, October 5, 1937.

14Hogeboom, F. E., Is Teen-Age Caries an Endocrine Problem?, J.A.D.A. and Dent. Cos., 24:422-428, M arch 1937.

15Boyd, J. D., Drain, CO. I., Stearns, G., Metabolic Studies of Children with Dental Caries., J. Biol. chem., 103:2, 327-337, Dec. 1933.

16Kugelmass, I. Newton, Dental Caries in Children, N.Y. St. Jrl. of Med., 37:20, 1735, October 15, 1937.

17Drain, C.L., and Boyd, J. D., J.A. D.A., 17:738, 1930.

18Hanke, M. T. et al., Dental Cosmos, 75;625, 933, 1933.

Hanke, M.T., The Attainment of Dental Perfection, Nutrition and Dental Health, May 1937.

19Mellanby M. and Pattinson, C.L., Brit. Med. Jrl., 1, 507, 1932.

20Howe, P. R., J. A. D. A., 20, 233, 1933.

21Hanke, M.T., The Attainment of Dental Perfection. Nutrition and Dental Health, May 1937.

22Panel Discussion, J. Pediatrics, 5,841, 1934.

23McCollum, E.V., Fundamentals of Nutrition, Internat. Clinics, 2:1, 1932.

24Mellanby and King, Brit. Dent. J., 66:538, 1934.

25Rosebury and Karshan., J. Dent. Res., 11:149, 1931.

26Hanke, M. T., J.A.D.A., 19:957, 1930.

27Harris, L.J., Brit. Med. J., 1:36, 1933.

28Kugelmass, I. Newton, Denal Caries in Children, N.Y. State Jrl. of Med., 37:20, October 15, 1937.

29Mellanby, May, Diet and the Teeth., Med. Research Council, Spec. Report Series 140, p. 306, 1929.

30Kugelmass, I. Newton, Dental Caries in Children, N.Y. State Jrl. of Med., 37:20, October 15,1937.

31Anderson, P. G., Williams, C.H.M., Halderson, H., Summerfeldt, C., Agnew, R.G., The Influence of Vitamin D in the Prevention of Dental Caries, J.A.D.A. 21:1349-1366, August 1934.

32Hawkins, H.F., Dental Survey, p.27, February 1931.

Hawkins, H.F., Some Important Assimilation Factors in Caries control, Nutrition and Dental Health, p.8, June 1937.

33McCurdy, G. G., Human Origins, Appleton, New York, 1924.

34Klein and McCollum, J. Dent. Res., 13:69, 1933.

35Schnak, J. Am. Dent. Assoc., 19:62, 1932.

36Tisdall, F.F., Prevention of Dental Caries and the Improvement of Health by Dietary Means, Pa. Med. Jrl., December 1935.

37Bricker, F.A., Importance of Mouth Brushing, J.A.D.A. 23:2287-2290, December 1936.

38Guerini, Vincenzo, History of Dentistry, Phil., Lee and Ferbiger 1909, p.25.

39Brekhus, P.J., and Armstrong, W.D., Civilization-A Disease., J.A.D.A. 23:1459-1470, August 1936.


A Case of Accidental Caries in a Dog

In the December issue of the British Medical Journal, Dr. Horton Pickett, 28 Eversfield Place, St. Leonards-on-Sea, England, reports a very interesting case of caries in a dog, which in all probability was due to mal-nutrition. he states:

“At the armistice we settle down for a week at Maubeuge, and my particular billet was in a house where there was a family, which included a body and two girls. They also had two dogs, a husky of the type used abroad to draw milk carts, and a dog of the Pomeranian variety. I must mention, for the benefit of those who do not know the district, that this town had been in German occupation since 1914. In about 1916 the Germans ordered all dogs to be destroyed, but the family refused to obey this order, and kept the dogs hidden in the house. They told me that they had kept them in cupboards, in the cellar, and in the eaves of the roof for weeks on end, and the dogs had on that account had no exercise. During the last two years or so food had got scarcer, and they were not able to get meat for the dogs, and towards the end of the war the diet of both dogs and family was almost entirely vegetable-potatoes, turnips, and swedes, etc.”

“The interesting part to me was the effect this diet and lack of exercise had on dog’s teeth, for both of them showed a most extraordinary amount of caries in all their teeth, and apparently on all parts of the teeth. For example, the labial aspect of the canine teeth from the gingival margin to the tip of the crown was entirely carious, and also added to the caries was a large deposit of calculus.”

“I was interested enough to wonder whether the same carious state was to be seen in the family’s own teeth, and much to their amusement demanded to be allowed a superficial examination. As far as I could see, with the two girls (aged 23 and 25), and the boy (19), there was no marked caries, nor any signs of anything out of the ordinary in the dental attention they had received.”

“An interesting question arise- were the humans exempt from caries on account of tooth paste and brushes, or was it the active energetic life they had led, keeping the blood in better condition, that gave them their protection, while the dogs, compelled to live unhealthily inactive, lost the power of the blood to protect their teeth from caries?”

“Unfortunately at the time I had neither the necessary knowledge, or interest, to weigh up any evidence there was to be found there, and treated it as only of casual interest.”


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