Kevin W. Toal, DDS, FADSA, FAAHD
St. Louis, Mo.
A letter of mine published in the December 1999 issue of Dental Economics noted that neither participant in the series of debates on amalgams/composites mentioned that composites are estrogenic.
In the March issue, Dr. Scott McAdoo of Denver accused me of not being factual, of not listing a reference, of creating a factoid, and criticized a study that he implied that I was not aware of.
First, I did not list a reference for the sake of brevity. The subject had appeared with Olea as a citation three times since 1996 in the Journal of the American Dental Association - by Habib in September 1996, by Nathanson in a cover story in November 1997, and by Soderholm in February 1999.
Secondly, while none of these articles criticized Olea`s methods as Dr. McAdoo did, it should be known that, in order to elutriate a given chemical to be used in testing on given cell lines, it is necessary to - as in Olea`s study - use extremes in temperature, acidity, and alkalinity to determine if the chemical can indeed be elutriated. Then one can determine the effect that chemical would have on given cell lines.
If these chemicals to be studied can be elutriated in any concentration and if they can adversely affect a given cell line, then it must be assumed that a given percentage of our patient population could be susceptible to the adverse effects of that chemical.
It should be well known that there is a very wide variability in patient responses to drugs and chemicals.
Thirdly, Nathanson, in his article, stated, "The study (Olea) confirmed the estrogenicity of Bisphenol A or BPA and also implicated Bisphenol A Dimethacrviate or BIS DMA as an estrogenic factor." And, while Soderholm concluded that, "current findings that the short-term risk of estrogenic effects using BisGMA-based resins, if insignificant, research should be directed at evaluating the pharmacokinetics and pharmacodynamics of the long-term release of contaminants from BisGMA resins (that is Bisphenol A) used in the mouth."
Enthusiasm to "convict" dental composites of adverse estrogenic effects should be no greater than enthusiasm to redeem them, and vice versa.
However, further studies must be done! The dental profession must be aware of any potential hazards in the use of dental composite.