Do you have unattractive dark lines around the edges of your crowns and wish they could be removed? The dark lines you see are from the metal coping underneath the crown or bridge, which provides extra strength. Removing the dark lines caused by crowns is one way to perfect your smile. This can be done by replacing the old crowns with all porcelain crowns. It may be possible that you have multiple teeth with dark lines. We would recommend replacing all of your old crowns at the same time so we can customize and match your existing teeth accurately to create a natural-looking smile.