When a tooth is over 50% filling it has been weakened and is at risk for fracture.
In these situations it is recommended to have the tooth covered by a Crown (cap).
A crown can be made of many different materials depending upon the desired outcome to help prevent a fracture and eventual loss of the tooth.
A crown can make your tooth stronger as well as make it look better. It can protect a weak tooth from breaking or restore one that is already broken.