There are limits to its usefullness. Teeth wear down pver time. This may repair a cavity but cannot rebuild a tooth mechanically worn away with age or with fractures, often a result of cavities. Fillings may be less needed but crowns (i have three) arent going away.

Teeth are not perfect. If i was going to mars id have them all either crowned or replaced with implants. Teeth are strong, but not stronger than metal.