Most composites are estrogenic (bisphenol-a). Some composites and tooth sealants are estrogen-free. I believe DiamondCrown/DiamondLite are estrogen-free.
Some think high gold is safest because it lasts a very long time, and composites are just temporary fillings that need replacing often on a downward spiral to root canals and implants...
Porcelains are good but need more tooth material to be drilled out.
Cost, time also are factors. Gold and porcelain are pricey and need two appointments to place a filling, composites only need one appointment. Cerec ceramics take one appointment but it's a loooong appointment because you wait for the filling to be made in a machine.