Will gum recession or "black triangles" cause by temporary veneers grow back or will the permanent veneer cover issue? (photos)

While your gums will not grow back, the permanent veneers should cover these spaces better.  Black triangles should always be taken into consideration when prepping and placing veneers.  I tend to make the teeth slightly wider in those areas to cover the spaces.  It makes for a very beautiful smile to widen the teeth and cover the spaces.I hope this helps.  Follow me on RealSelf if you have more questions.

Generally, the permanent veneers should and can be contoured at the gingival margin to give the tooth nice contours and fill in any black triangles. I have seen temporaries push the gum tissue slight causing some space and it heal and fill out nicely after about 2 weeks. Be sure to look at your final veneers tried in your mouth before final cementation with your dentist  to make sure you are happy. Good luck!

This is hard to say, as I do not know the extent of your gum problems in the past. As a Cosmetic Dentist,  I am able to direct my lab technician using a lot of photos and my prescription.  I would say that you can't have the central incisors as thin and pointed where they are contoured along the gingival margin. The line angles could be changed to help "plump" up the interproximal gingiva to reduce any black triangles. Be sure to look at your new veneers on your teeth with your dentist before agreeing to having them permanently cemented. They can be sent back to the lab and changed or recontoured if they appeared to be showing too much of this dark triangleDouglas Jopling,  DDS Dallas,  Texas area