One of the most conservative, biocompatible and durable filling materials available to restore teeth is cast gold. Gold is a noble metal so it does not react to the acids and enzymes found in the mouth. Gold does not wear down opposing teeth and it can be finished to a relatively seemless fit to the tooth. My own mouth was restored with excellent gold restorations over 30 years ago. They are still working great. Please be sure to ask about using gold to restore your own mouth.