HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Barr, D. B. Articles by Joskow, R. Search for Related Content PubMed Articles by Barr, D. B. Articles by Joskow, R.

The letter from the ADA Division of Science regarding our article presents an interpretation of publicly available literature data that differs from our interpretation.

We agree that Schmalz and colleagues¹ did not analyze any dental products. However, their study did not determine that "BPA was not found in bisphenol A glycidyl dimethacrylate (bis-GMA)," as written in the letter. Instead, as stated in the abstract of the Schmalz and colleauges¹ article, the study results showed that "bis-GMA-monomer and BADGE [bisphenol-A diglycidylether]-monomer from one manufacturer did not contain any detectable amounts of BPA (< or = 2 ppm [parts per million]); bis-DMA and BADGE-monomer from a second manufacturer contained BPA quantities of 4–155 ppm."

The 2-ppm limit of detection (LOD) is higher than our method’s LOD by more than three orders of magnitude. Assuming we have the same accuracy base, it is therefore possible that some residual BPA (at or below low ppm levels) may be present as an impurity in commercially available monomers used in dental products, but at concentrations that are not detectable, unless a more sensitive analytical method is used. Detection of trace concentrations of a substance is strongly dependent on the sensitivity of the analytical methodology, thus stressing the importance of using highly sensitive analytical techniques such as those we employed for the research presented in our article, and for which we were commended in the letter.

We do not wish to have the differing interpretations of the background information detract from our article’s central message, with which the ADA Division of Science seems to agree: that the use of Delton LC for dental sealants may produce a low-level point source exposure to BPA. The exposure levels we found were approaching those lower doses used in newer animal studies reporting adverse effects.^2–4

We continue to believe that dental sealants are an important part of routine dental care, and any potential exposures can be reduced or mitigated by active elimination of saliva after sealant placement.

	REFERENCES

TOP REFERENCES

1. Schmalz G, Preiss A, Arenholt-Bindslev D. Bisphenol-A content of resin monomers and related degradation products. Clin Oral Investig 1999;3:114–9.[Medline]
   
   
2. Palanza PL, Howdeshell KL, Parmigiani S, Vom Saal FS. Exposure to a low dose of bisphenol A during fetal life or in adulthood alters maternal behavior in mice. Environ Health Perspect 2002;110 (supplement 3): 415–22.
   
   
3. Vom Saal FS, Hughes C. An extensive new literature concerning low-dose effects of bisphenol A shows the need for a new risk assessment. Environ Health Perspect 2005;113: 926–33.[Medline]
   
   
4. Vom Saal FS. Bisphenol A eliminates brain and behavior sex dimorphisms in mice: how low can you go? Endocrinology 2006;147: 3679–80.[Free Full Text]
   
   

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Barr, D. B. Articles by Joskow, R. Search for Related Content PubMed Articles by Barr, D. B. Articles by Joskow, R.