A Report of The “Caries Clinic”


D. D. S. R. A.

Dental Therapy Editor

            A report from a group of Investigators of Northwestern University College of Dentistry, gives of the Anniversary of this is of great significance.

“This program involves a numbers of groups of teachers and research workers is the basic science fields, all of whom are interested in dental problems. Their studies are coordinated under the direction of the whenever a study is understand which calls for the cooperative effort of two or more departments.


The personnel for this group study of caries, which began five years ago, is as follows: Edward H. Hatton, professor of pathology and bacteriology; Earl A. Zaus, professor of physiology; William G. Skilica, professor of histology; Harold I. Hansen and Leonard S. Fosdick, professors of chemistry; Miss Charlotte Epple, bacteriologist; and the assistants in each department; also Dr. Clara M. Davis, pediatrician and nutritionalist. The clinical staff of the school is represented by Robert E. Blackwell, professor of operative dentistry, and his associates, E. Bedmer, Jr., and Z. M. Shafer. Two graduate students, George D. Wessinger and Goerge W. Teuscher, also participated in the studies during the past year.

The majority of this group regularly on Thursday mornings of each week for a “Caries Clinic”. The clinical instructors studied each patient and rated him as in caries susceptibility, after which bacteriologist took cultures and chemists secured spectrums of saliva for their tests. There was also a general discussion of the progress of the various phases of the investigations.

The patients for this clinic included: regular patients of the dental school, selected especially for the “Caries Clinic” each week; students of the school, selected in groups of from ten to thirty, for special studies extending over various periods up to a full school year; about seventy-five children in an orphanage, and about one hundred boys at a boy’s farm located about seventy miles from the Children’s Memorial Hospital of Chicago. A special dietitian was employed over a period of six months to keep and tabulate diet charts.”

An introduction and preview of the studies reported, is given by Dean Block, wherein a review of the various theories advanced as the cause of dental caries covering a period of the last thirty or forty years and more, up to the present time. To quote from Dr. Black –

“In more recent years many investigators have made progress in the study of various mouth organisms which appear to have a definite part in the caries process. As yet no agreement has been reached as to the exact organism or organisms, which, to the exclusion of others, may cause dental caries, although a number of investigators of dental caries believe B. acidophilus to be the specific organism. As will be noted in several of the reports to be presented, it seems probable that no single organism can produce caries, and it may require very extended chemico-bacterial studies to determine each of the steps in such a very complicated process. In the meantime, may very extensive studies have been made by those who believe that caries may be controlled by modifying the diet. The broad basis of their belief lies in the statements that human beings may become more susceptible as a result of the dietary refinements of modern civilization, and that the teeth of animals do not decay. Apparently, practically all nutritionalists ignore the findings of Miller, Black, and Williams, and particularly the studies of Black, Tomes, and Williams as to the structure of the teeth. They endeavor to increase the calcium salts in the enamel by the use of vitamins, by the addition to the diet of natural foods containing calcium, and by other means. Only in recent years has it been suggested by a few of this group that whatever success they may have attained might have resulted from the effect of certain vitamins of foods upon the saliva rather than on the structure of the enamel. It may be said that the nutritionalists, as a group, have overlooked the possibility of modifying the saliva and thus changing the environment of the tooth.

The studies presented herewith really began where Miller, Black, and Williams left off more than twenty-five years ago.

Studies of saliva present unusual difficulties, because, as Dr. Hansen states, “its composition is dependent upon so many factors that it is impossible to assign to it definite analytical figures.” The composition saliva is so variable that no two analyses will exactly agree.

Because of the difficulties involved, very little use is made of the saliva in medical diagnosis. THE STUDIES BY THIS GROUP HAVE DEVELOPED A UNIQUE AND DEFINITE DIAGNOSTIC USE OF THE SALIVA. There appears to be no question as to the reliability of the test for susceptibility to dental caries, which is discussed later.

The fact that two parts in a million of fluorine in drinking water causes mottled enamel suggests that the actual variations in the saliva which represent a change from immunity to susceptibility to caries may be very slight and difficult of discovery. However, it seems possible that considerable progress may be made in caries control by experimentation with various foods and other health measures, with only the present chemical test as a guide.

Very brief statements of the most important findings by those engaged in these studies are presented in the following paragraphs:

  1. A PLAN FOR MAKING CLINICAL EXAMINATIONS was formulated, by which the most reliable estimate of susceptibility of each person to dental caries may be recorded. In these studies, the majority of the examinations were made on the first and second visits of the patients to the “Caries and Clinic.” It should be pointed out that the dentist in private practice should be able to make a more accurate estimate, because of his opportunity to study patients over longer periods of time.
  2. TEST TUBE STUDIES OF BACTERIA indicate that the bacillus acidophilus, or any other single organism, cannot produce decalcification of the enamel at a rate at all comparable to that of saliva from susceptible persons; also that the bacillus acidophilus and yeast together produce and most rapid decalcification, and at a rate comparable to that of saliva from susceptible persons. In several of the reports reference will be made to these two organisms, studied from various viewpoints.
  3. The free SALIVA has ability to neutralize acids, yet it is recognized that in AECLUDED AREAS (pits and fissures, proximal and gingival third regions) the acid will not be so readily dissipated. This is related to Williams’ “bacterial plaques” and Miller’s “retention centers.”
  4. THE SALIVE OF SUSCEPTIBLE PERSONS AND THAT OF IMMUNES CANNOT BE DIFFERENTIATED BY ANALYSIS. However, there is a MARKED DIFFERENCE in the rate at which the two produce acid and thereby dissolve enamel in a four hour test. The saliva of persons immune to caries dissolves practically no calcium, while the saliva of susceptible persons dissolves large amounts of calcium. It is on the basis reaction that the DEGREE OF SUSCEPTIBILITY TO CARIES is estimated.
  5. ALL CARBOHYDRATES in the mouth may be fermented into acid. This is a chain reaction, and there are probably five steps. These reactions are cause by enzymes, and most mouth organisms do not contain or excrete all the enzymes necessary for rapid decalcification. The bacillus acidophilus and yeast are most frequently associated in rapid decay. Enzymes are a PRODUCT of bacteria –not the bacteria themselves.

PHOSPHATASE is an important enzyme. The study of this enzyme shows that yeast is high in phosphatase production, while B, acidophilus produces little or name.

PYRUVIC ACID is recognized as one of the products f sugar fermentation. Yeast and bacillus acidophilus consistently reduce more pyruvic acid to lactic acid than any other organisms studied.

The accumulated evidence indicates that the bacillus acidophilus and yeast are most likely the principal cause of lactic acid formation.

  1. SUGAR from food may remain in the mouth for an hour, and the length of time that sugar remains in the mouth is in relation to the degree of susceptibility to caries. In passing, it is interesting to note that the chewing of gum for a few minutes after a meal reduces the time that sugar remains in the mouth.

The question may very properly be asked as to the practical value of these researches. In reply, the following may be listed:

  1. THE CHEMICAL TEST FOR SUSCEPTIBILITY is the most important basic factor for all future studies of caries; it is an accurate test of the susceptibility of a person at the time of the test.
  3. It  should be possible GRADUALLY TO REDUCE THE SUSCEPTIBILITY of individuals, or groups of children in institutions, and the measures employed should eventually be crystallized into a PROGRAM OF PROCEDURE in the study and treatment for the prevention of caries.
  4. The test should, in due time, be made AVAILABLE FOR ALL PRACTITIONERS. It should be possible, as a result of further study, to develop a plan by which chemical tests of the saliva may be made in local pathological laboratories.
  5. SUGGESTIONS REGARDING DIET STUDIES BY PRACTITIONERS. For the present, the following suggestions are offered in relation to the diet:

Emphasis should be placed on simple, natural foods, rather than refined or processed foods. Most children prefer the former.

Reduce refined and highly purified carbohydrates to the necessary minimum. (In one of the studies at a children’s home the consumption of sugar was reduced from four barrels to half a barrel per week, fresh fruits being substituted.) Sugar consumption in the United States has increased from 11 to 115 pounds per person per year in the past one hundred years.

Insist on an ample supply of fresh fruits and vegetables to guarantee sufficient vitamins and minerals.

Recommend a varied supply of high grade protein foods, including milk, milk products, and glandular meats.

Accessory vitamins should be prescribed only in off seasons whom fresh fruits and vegetables are not available or are too expensive. Vitamins A and D may be given during the winter.

The use of mineral tablets –calcium and phosphorus –should not be necessary and should be employed only in special cases under professional direction.

The final result of these studies will undoubtedly be of great benefit to the dental profession and may be far reaching in benefiting humanity not only in the preservation of the teeth but in doing so bring about a greater bodily health. As I think we must agree that strong healthy teeth and accompanying healthy gum conditions go hand and hand with a general well being.

Northwestern and Dr. Black should be congratulated for having instituted this work.



Did you know that there are green, orange, pink, cream-colored, yellow, speckled and streaked bananas, some of which taste like peaches, apples, pears and roses? They grow in Jamaica, B. W. I., where one can eat a banana every day in the year and never taste the same variety twice.


The eggs of the dragon fly are made into croquettes in Mexico. They are safe to taste like shad roe. Katydids, rolled in a tortilla, are another delicacy.