Whats too much fluoride?

April 1, 1997
In regards to the article titled, "Are our patients guzzling too much fluoride" (February 1997), the authors state that the ingestion of fluoride can cause symptoms ranging from mild gastric distress to arrhythmias, muscle tetany, parathesia, coma, and convulsions. They also state that 5 milligrams (mgs) per kilogram (kg) will cause mild gastric distress; 15 mg/kg requires a patient be admitted to a hospital.

Dear RDH:

In regards to the article titled, "Are our patients guzzling too much fluoride" (February 1997), the authors state that the ingestion of fluoride can cause symptoms ranging from mild gastric distress to arrhythmias, muscle tetany, parathesia, coma, and convulsions. They also state that 5 milligrams (mgs) per kilogram (kg) will cause mild gastric distress; 15 mg/kg requires a patient be admitted to a hospital.

Finally, the authors claim that leaving 16.9 mgs of fluoride in the mouth of a 6-year-old after a fluoride treatment could be fatal.

I made this chart for them to see.

Weight / mgs causing gastric distress / mgs causing cardiac and neuro complications

-----------------------------------------------------------------------------------

1 lb. / 11 / 33

10 lbs. / 22.7 / 67.5

25 lbs. / 56.8 / 170.4

50 lbs. / 113.6 / 340.5

60 lbs. / 163.5 / 409

75 lbs. / 170 / 510

The authors make reference to studies - none of which are cited. Their statement that the fluoride in carbonated drinks is causing fluorosis is careless without really looking into and researching the facts. Many of us remember how bad coffee, eggs, and alcohol were for you only to learn later that coffee, eggs, and alcohol have beneficial properties.

I suggest the authors take a course in reading and writing research papers and refine their math skills before writing another paper. It is articles like this that cause hysteria among patients and confusion in the field of dentistry.

Katherine R. Jordon, BS, RDH, BSN, RN

New York, New York

Editor`s Note: We asked the authors to respond to the above. First, though, we would like to point out that RDH publishes references for all articles in an issue in one location, instead of at the end of articles. While this may cause confusion among readers, the location of the references is listed in the table of contents. In this case, the references were printed on page 54 of the February issue.

The authors, Mary D. Cooper, RDH, and Connie Myers Kracher, CDA, responded to Ms. Jordon`s letter by writing:

"The concern with fluoride, with children under 6 years of age, is that they have a greater incidence of accidental ingestion of fluoride products. That is why many over-the-counter fluoride rinses state restrictions within a cautionary label to avoid swallowing and that children younger than 6 years old should not use the product.

"The claim in the article that 16.9 mgs of fluoride can be remaining in the child`s mouth after a professional topical fluoride treatment via a tray application was researched by LeCompte (as listed in the references on page 54). The authors` claim is that this level could be toxic to a young child, not fatal as you stated.

"There are different meanings to these two words. Toxicity means `affected by a poison or toxin` and has several levels or degrees, ranging from mild to severe - which could lead to fatality. Fatal means `causing death.`

"A toxic reaction could be recognized by symptoms of nausea, followed by vomiting. Again, the weight of the young child and the actual amount of fluoride ingested will be determining factors as to how the child may react. That is why the authors gave specific guidelines for the professional applications of fluoride gels. As stated in these guidelines, expectoration is the single most effective way of removing retained fluoride orally, followed by oral evacuation, and is of utmost importance in preventing the child from ingesting fluoride.

OThere are several references that state the increase in fluorosis is from multiple sources ? most commonly from the use of fluoridated toothpastes, rinses, supplements, and an increase of fluoride from the diet ? including food processing and carbonated drinks.

OThe combined use of these exposures has increased the incidence of mild fluorosis. The authors did review several recent publications in dental research in this area that will reiterate the above implications regarding the increase in fluorosis. The issue regarding food and beverages contributing to mild fluorosis has been documented in numerous publications in refereed journals. Some of the references are cited in our article. However, there are several in addition to the references that we submitted. We refer you to articles published within the last couple of years, regarding fluorides from the Journal of Public Health Dentistry. This journal is one that fluoride Oexperts? publish in most frequently.

OThe authors had no intent to alarm the profession or cause Ohysteria,? but to stress the importance of proper guidelines in administering professional fluoride when considering multiple sources to help decrease the incidence of fluorosis and or toxicity.O