Exchange: Bibby and Radike, JADA 1956

The following exchange between Radike and Bibby shows the truth on sodium fluoride’s “benefits” in toothpaste on caries...Proctor & Gamble had financially supported Bibby’s research on sodium fluoride in toothpaste...based on the abysmal findings they then chose to support Muhler’s research at the University of Indiana who used “stannous fluoride” instead (“Crest”).

   “Shaw, Wellock and Bibby concluded that a sodium fluoride dentifrice had no value in the prevention of dental caries. This is not the case. The table, which is the source of Muhler's information, presents evidence also of a 20 per cent reduction in new cavities after use of a sodium fluoride dentifrice. The conclusions that we drew from the conflicting results were (a) that clinical studies need repeated confirmation and (b) that no therapeutic dentifrice works unless it is placed on the toothbrush and used in the mouth. This conclusion is not in conflict with my present opinions that a sodium fluoride, other fluorides or other agents which react with the tooth surface, when suitably combined in dentifrices, should be effective in combating dental decay. Beyond that, it should be pointed out that the use of an addendum to quote unpublished material is an indirect and unusual way of presenting scientific evidence. Such an indirect quotation generally is reserved for those who are dead or residing behind the Iron Curtain and certainly is not justified when the authors of the unpublished material are available for direct consultation. The method of quotation is sufficiently unusual, particularly when coupled with failure to quote opposing evidence from the same source, to suggest that the authors' concern for the promotion of an idea (or even a product) had taken precedence over the establishment of scientific fact.”

Basil G. Bibby, D.M.D., Rochester, N. Y.
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DR. RADIKE COMMENTS ON DR. BIBBY'S LETTER

The following data are needed to round out the information relative to clinical tests with sodium fluoride in a dentifrice. All of these studies were supported by Procter & Gamble, and, therefore, I am able to give a detailed summary of the results. In 1942 a clinical test, under the direction of B. G. Bibby, was conducted among orphanage children 4 to 16 years of age and among dental students. In all of these studies the group was divided approximately in half, half using the fluoride dentifrice and half using a control dentifrice. During the first year, 69 children using a dentifrice (Teel) containing 0.01 per cent sodium fluoride showed a 23 per cent increase in caries.

During the second year, the concentration of sodium fluoride was raised to 0.1 per cent, and the group showed a 17 per cent reduction in caries. The 48 dental students using a 0.01 per cent sodium fluoride tooth paste during the first year showed an 8 per cent increase in dental caries. When using a 0.1 per cent concentration during the second year, they showed a 20 per cent increase in caries. Another group of dental students using sodium fluoride in Teel showed a 12 per cent increase in caries the first year and a 14 per cent increase in caries the second year. In 1946 a second test was started under the direction of B. G. Bibby and W.D. Wellock among school children 9 to 14 years of age. At the end of one year, 122 children who used a 0.1 per cent sodium fiuoride tooth paste showed a 23 per cent reduction in dental caries and at the end of the second year showed a 6 per cent reduction. None of these results, ranging from a 23 per cent reduction to a 23 per cent increase in caries, were statistically significant. At this point representatives from the Procter & Gamble Company along with B. G. Bibby, W. D. Wellock and R. S. Manly of Boston and Rochester decided that a large-scale clinical test of a sodium fiuoride dentifrice was indicated in order to prove definitely whether or not sodium fluoride is effective when used in this way. It was expected that results of such a study would resolve the doubt raised by the inconclusive results obtained previously. In 1948, a test was started under the direction of W. D. Wellock with about 2,000 school children 7 to 13 years of age. At the end of one year, 946 children who used a 0.1 sodium fluoride tooth paste showed a 9 per cent increase in caries as compared to the caries of 969 children who used a control paste. The results of this large-scale test, which I believe was well conducted, are the most important results available to date for a sodium fluoride dentifrice. We have requested that these results be published in detail, but the investigators have not yet done so. The reference by B. G. Bibby to the negative result of this test in the American Association for the Advancement of Science publication, Fluoridation as a Public Health Measure, is the only published mention of this test of which I am aware. It was added, therefore, as an addendum to the Muhler article in J.A.D.A. 51:559 November 1955. We did not consider it important to review the other five prior test results in this same article because they all represent small-scale clinical tests by B. G. Bibby and others in which the investigators failed in every instance to show a significant difference between experimental and control dentifrices. The conclusion indicated by all the sodium fluoride dentifrice tests summarized by B. G. Bibby in the AAAS publication must be that a significant reduction in dental caries through the use of a sodium fluoride dentifrice has never been demonstrated. This is precisely the tone of the addendum in Muhler's article to which Dr. Bibby seems to object. I might add that we have spent many months analyzing the sodium fluoride dentifrice data summarized by Dr. Bibby, and I am confident that our statements indicate the proper conclusion from these studies.

A. W. Radike, D.D.S., Drug Products Division, The Procter & Gamble Company

J.A.D.A. 52 (Feb. 1956) 243-4
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FLUORIDE DENTIFRICES

Some time ago I criticized the "addendum" to the article by Muhler and others published in the November 1955 issue of THE JOURNAL. Radike's reply to my criticism (THE JOURNAL, February 1956) strengthens rather than weakens the points I tried to make. First of all, it shows that the study I felt they should not have quoted was known to them for many years and, therefore, they had plenty of time to obtain my interpretation of it. It also reveals that the 23 per cent reduction obtained in the study I felt should have been mentioned along with the one they actually quoted did, at one time, seem important to Procter & Gamble, for apparently it was this observation which prompted the company to offer financial support for our clinical studies, which until that time had been "supported" only to the extent of free dentifrices. Although the listing in Radike's letter of the negative observations in our pilot studies on the use of dentifrices to which sodium fluoride had been added probably was designed to create further doubts as to the value of sodium fluoride as a dentifrice constituent, it also strengthens a point made in my letter, namely, that fluorides must be "suitably combined in dentifrices" in order to be effective. That Procter & Gamble has had difficulty in doing this with sodium fluoride is suggested by the risky nature of the fluoride dentifrice formula (Crest) which it is now marketing. Certainly, if it were not necessary to use a highly acid dentifrice (as low as pH 5.3 in Rochester samples) in order to get a fluoride effect, the resultant risk of increased tooth brush erosion would not be run. Neither is it likely that if it could have been avoided, the company would choose a dentifrice formula which, on the basis of laboratory tests, will cause darkening of the teeth in some dentifrice users. Since my interpretation of our own sodium fluoride dentifrice studies has been questioned, a restatement of my views is probably in order. They follow:

1. It was a mistake on my part to include the results of two unpublished studies in our tabulation of fluoride dentifrice results.

2. The negative results of our studies led us to believe that the dentifrice base was very important in determining the effectiveness of added fluorides. They also suggest that the relative effectiveness of different fluorides cannot be reliably compared by studies such as those of Muhler and others in which different fluorides are combined in the same dentifrice base.

3. Dentifrice tests should be carried out in groups of children who are encouraged to clean their teeth either by parents or as part of an existing school dental hygiene program. If this is not done, dentifrices probably will not be used, and results become meaningless. It is because we had no evidence that the dentifrice was used to any significant extent in the study quoted in the "addendum" (Wellock and Bibby's study, 1948) that we declined to publish a full report on it. In my opinion, the study was not "well conducted" as Radike believes, and the observations have less value than those of the first year of our 1946 study in which it is known that the dentifrice was used.

4. Knowing that we did not believe the two studies in question were sufficiently sound to be "published in detail," it was out of order for the authors to base possibly misleading interpretations on one of them without either quoting the order or inviting a direct comment from us.

5. A useful purpose could be served by encouraging a full discussion in these columns of the claims and hazards of various fluoride dentifrices.

Basil G. Bibby, Rochester, N. V. J.A.D.A. 52 (1956) 755