Other solutions for getting rid of black triangles between teeth? (Photos)

The dark triangles between your two front teeth could be easily handled with either braces or invisalign and a very small amount of reshaping of the front teeth.    This would not make your smile narrow as some suggest, and Bioclear (which is a brand name of bonding material) would make your teeth look very square.  The amount of treatment would be minimal thus be a short treatment time (from what can be seen in the photos.)

Hello,
"Black triangles" are formed between teeth when the gum that is supposed to fill in the triangle between teeth disappears, which means the bone underneath the black triangle has also been lost. Regular cleaning and flossing can keep the gum and bone healthy and preserve the bone around the teeth. To fix black triangles following are the options:
1. Veneers- These can be very conservative and much more permanent than bonding. They can also be done in a shorter treatment time than Invisalign.
2. Invisalign with some IPR ( the IPR can be done between the front two teeth if it will not create spacing between your other teeth.)
3. Orthodontics with conventional braces

Unfortunately one of the unwanted side effect of invisalign is black triangles. So I believe doing invisalign makes your situation worse. I don't think the triangle is any problem as long as your dentist thinks the bone level & probing around these teeth are healthy. Looking at the photo your gum seems healthy but xrays & clinical exam (probing) are necessary to confirm.

Most dentists would agree that the best solutions are usually the least invasive.  If we can avoid invasive treatment, we suggest that first.  In this situation, Bioclear would be a great choice.  To do braces again, and slim/polish the shape of the teeth, will require making the arch more narrow (close the space that was just created), however this has a domino effect to the lower arch.  It takes something very minor and creating a tremendously complicated solution.  Bioclear will fill in the spaces and last a very long time.  A third option is porcelain veneers, but the cost and required removal of enamel makes that a "last resort" type of treatment.