Well, I just talked to a dentist... She said they use composites to replace any fillings that take up 50% of the tooth, a crown will be required. They use
zirconium-oxide Cerec or Cerec Vita (ceramic) crowns - depending on their evaluation of best compatibility with the patient. Each crown costs $1250. BTW, from the research I've read, pretty much NO filling is 100% safe. ...