A mercury free dentist I corresponded with on email, who is trained in oral toxicology and understands the need for biocompatible materials, said he used only two main materials in his office to replace mercury/fill cavities.

Cerec porcelain inlays/onlays, or heliomolar HB (which is a composite, but apparently strong and reliable) and I think optibond (for the bonding material). but each dentist no doubt has his/her own particular materials they prefer to use. This dentist reckoned that these materials seem to suit most patients and he's had less problems with them.

I myself am not certain of any of them. I have cerec in my mouth after getting some old/worn composites redone. Not sure, but certainly I've not improved in anyway in health, so they were evidentally no better than what I already had biocompatible wise, but mechanically they are a stronger/durable material and can last up to a lifetime. But they apparently contain aluminium oxide and I cannot vouch for the safety in that respect, particularly as there are other sources of aluminium many of us are exposed to.

Very tough to make a decision. I chose from a serum compatibility test (blood serum testing by Clifford labs). I also had another test done, so I tried to chose the best out of what showed up ok on both forms of testing. I still am not 100% that what I have in my mouth is not affecting me in some way....

I guess it is very much down to the individual's own biochemistry.