Front Tooth Yellow Again After Internal Bleaching Should I Get It Done Again or a Crown Etc? (photo)

Don't bleach again - the risk is too great. If there isn't a big filling in the tooth, do a veneer instead of a crown. You can bond the next tooth to help close the space, or the best cosmetic solution is veneer both central incisors for a perfect match.

If your tooth has discolored more you can certainly consider repeating the bleaching procedure again.  However, there is a slight risk that with repeated internal bleaching that the tooth could become damaged by a process called internal resorption.  So there is some downside risk to continually repeating the internal bleaching procedure.  External bleaching with trays or Zoom Bleaching, doesn't have nearly that amount of risk, so you might want to consider that first.  You can use tray bleaching, but only put the bleach in the section of the tray that goes over the discolored tooth.  Or with Zoom, they can cover over the adjacent teeth so that only the discolored tooth gets bleached (whitened).

Porcelain veneers are the most predictable way of correcting your problem.  It will fix the color and if you elect to do two (to close the space) then you will end up with the best resulting treatment.  Also, porcelain veneers are extremely color stable and I would not expect them to change color over time.

my recomendation its not to re do it, it will hardly get the same color, you should try metal free ,zyrconium crowns ,you will be very satisfied with this material, it looks very natural,and its also very strong, for that gap you have unless you like it, you can perform both centrals ,one , crown ,one veneer,you can close that gap, make them so natural, and they would look great!!!