Periodontist Removed 2mm From Gums, Now There Are Black Triangles Between Teeth, Is This Permanent?

This question depends on a few variables to give you the correct info. Depending on how long ago the surgery was done then it takes time for the tissue to return to normal or final tissue height, this depends on type of surgery and amount of infection or inflammation present. You also need to be aware of the contact point of the 2 teeth in relation to the crestal bone. If the bone crest is 5mm or less from the contact then you will get the papilla back. 6mm or more of height makes the result a bit more unpredictable. So give it time, 6wks to 6 months to get final healing and hopefully things will be back to normal.

I think it must be determined what the treatment was for.  Some treatments are to reduce the bone around a tooth which can cause the triangles.  Also, if venerrs aor crowns are to be placed then the triangles can be filled by the porcelain.  I feel first and foremost, it needs to be established what the periodontal procedure was for then a determination can be made as to a good result or not. 

Black triangles are always a concern, particularly, in the front of the mouth (also known as the esthetic zone).  The distance from the contact point between the two teeth and the height of the bone between the same teeth is the determining factor on how the gum tissue will fill the space (or black triangle).  If this distance is greater than 5 mm, the gum tissue usually will not fill the space completely, which can result in a black triangle.  Restorative measures can be taken in order to shorten this distance if it is greater than 5 mm, which will allow the gum tissue to fill the space.  The esthetics of the restorations necessary to shorten this distance may not necessarily be an improvement over the current esthetics with the black triangles, however, so you should definitely discuss all of the options with the restoring dentist as well as the periodontist about the possiblity of additional surgical options.

The soft tissues between teeth often disappear after gum surgeries or braces.  While not considered pathology, it can be an aesthetic issue, and Bioclear can help fill in the gaps.  Crowns or veneers can help, but usually this is done if Bioclear proves unsatisfying.....