http://www.biodent.be/diamondcrown.html

DiamondCrown, DiamondLite, DiamondBond and DiamondLink do not contain any cytotoxic-metallic ion constituents, any evaporable methacrylic acid constituents or any chemistry that yields mucous membrane irritation, fibroblasts changes, epithelial changes, microabcess formation, lysis or haemolytic behavior. This is in contrast to many other commonly used dental restoratives.

Basically, the web site says that other composite materials may have the effects you are speaking of, but their materials do not. Read through it and see what you think.

To the best of my knowledge, this is the best biocompatable product out there short of extraction.
Hope this helps