Experts Discuss Bisphenol A

Reports suggest that BPA can leach from dental sealants and composites, especially immediately after the procedure is completed.

You are correct in that the critical window of exposure is during fetal and early childhood development, therefore as a precautionary measure, it seems reasonable that pregnant women avoid these dental procedures. Certainly they should discuss their concerns with their dental staff and physicians.

There are many, many sources of information about BPA in plastics on the Web. Some are from NGOs and others are industry Web sites. I would suggest that one just search on google or some other search engine for "BPA plastics" and read a variety of these from both sides of the issue to get a balanced idea of the controversy about this chemical and its purported toxicity. There is also information on BPA levels from dental sealants and other products.