Papillae loss and reconstruction options: I have gum disease. (Photo)

you have mentioned that you were told about 4-5 mm pocket in this area.   pocket depth could be due to inflammation with /or without presence of bone loss in between the teeth. when proper cleaning is done and the build up under the gum is removed, this inflammation will resolve and the gum will shrink resulting in decrease in pocket depth.  as the result the papilla will also shrink and leave a "black triangle" space.  gum/ bone grafting can not regenerate the missing papilla.  Some doctors have been using dermal filler sot plump up the papilla which will give you temporary improvement.  as you know the other option will be to fill the site with white filling and to broaden the contact between the 2 teeth.  

In your case there is no loss of bone, therefore, no need for regeneration or graft. Your formation of black triangle should be treated with an extra good cleaning care. 
Good luck,
Dr. Franco