Do all root canal treated teeth eventually go black?

Hi:All root canal teeth will change color over time.  How dark it is difficult to say.Best,Dr. Maddahi

Over time, most root canaled teeth will darken. The crown margin can be placed slightly under the gums to hide some of that. It may be years before you notice any change, if at all. Only time will tell.

It is not uncommon for teeth that have had root canals to turn dark. This does not usually happen immediately.Your dentist can take steps to try to keep the grey line from happening by using a more opaque porcelain.