What Are Porcelain Inlays/Onlays?

A porcelain inlay/onlay is a custom-made insert that perfectly fits
inside of a prepared tooth. It is securely bonded to prevent further
decay and stabilize the surrounding tooth structure, and it looks
completely natural.
Do I need Inlays/Onlays? If you have large metal
fillings that you want replaced or have larger cavities that you want
to make look
more natural and function more like your natural teeth, you may
want to consider porcelain inlays/onlays.