A. With teeth that are ground down, it is not a simple matter of just placing crowns on the teeth. There is often an underlying reason for the decreasing height of the teeth. This is often due to a grinding habit or loss of posterior support – i.e the loss of posterior teeth. This loss then causes more force / wear to be placed on the front teeth, and should the top teeth have porcelain crowns then the wear is accelerated.

Once the reasons for the wear of the lower teeth are addressed, then crowns – either cerec or normal crowns should last like any other.

I hope this clarifies things

Regards