The black triangle is always a cosmetic challenge. Porvelain veneers can correct the issue. You will be able to floss between the teeth after the veneers as they are separate restorations. When done well they are imperceivable to the eye and compatible with the gum tissue.
As an alternative you may want to speak to a periodontist about a gum graft in that area. You will need to balance the priorities in your mind as to how significant the black triangle is esthetically versus the solutions to improve upon it.



