My tooth had a root canal over 40 years ago and was shaved down to a peg, and was capped using a porcelain fused metal crown. The underlying tooth is severely discolored and dark. I now need a new crown and my dentist is recommending all porcelain. He is also encouraging me to choose a slightly lighter shade than my surrounding natural teeth to compensate for the discoloration since concerned of the possiblity of it showing through. I believe his crown color choice is too bright and want a darker shade. Is there anything my dentist can do to prep the underlying tooth, masking the discoloration and preventing it from showing through the new crown? Also, is an all porcelain crown the best option given this circumstance? I do not want another porcelain over fused metal crown as my experience has been that they eventually show dark lines at the gum margin.
For your information, I am having four crowns replaced on tooth numbers 7, 8, 9 (I believe this is the one he is concerned about; both front teeth have root canals but one was repaired using a metal post) and 10 due to severe gum recession and metal leakage. All are currently capped with porcelain over fused metal.