I had a frenectomy and gum graft 4 years ago. the gum graft receded. why? the dentist wants to do another frenectomy. is it really necessary?

More surgery?: My suggestion is to discuss this issue and have all your questions answered by the dentist who did the surgery and has been seeing you (hopefully) on a regular basis for periodontal maintenance. Then see a Periodontist (or another Periodontist) as the case may be for a second opinion and consult. Ask the same questions. At that point you should have sufficient knowledge to know what to do.

Probably: Your Dentist is there, looking at you. I'm not, and can't see what's going on. Additional gum surgery may be required. Have you considered a second opinion from a Periodontist, a gum/bone specialist?