Failure Could Be Catastrophic
Another good reason you shouldn’t wait for fillings to fail is that failure could be catastrophic. Metal fillings tend to be large because dentists need to have a fairly large hole to stuff this type of filling into. When these large fillings fail, it can seriously damage your teeth.
The nature of metal fillings also makes them more likely to crack your teeth. Metal fillings expand and contract more quickly than your natural teeth. When the fillings expand, they push on your teeth, which can crack them.
In most cases, repairing a tooth after this type of filling fails requires a dental crown, and sometimes root canal therapy. That’s if the tooth can be repaired: sometimes a tooth will be so badly damaged that the tooth might have to be removed. Then it should be replaced, usually with a dental implant.
However, if we choose to replace an amalgam filling before it fails, we can usually use a ceramic filling.