A free gingival graft will not work to cover the implant unless there is bone between the implant and the gum tissue.
My suggestion is to have a bone graft with guided tissue and bone regeneration to cover the implant. This would not only yield the best cosmetic results, but would strengthen the implant by better bone contact.
The other prosthetic option may be to have pink porcelain cover the exposed implant. I do not like this option. Maintenance is very difficult and worsening of gum tissue can occur.
Information contained within this reply is intended solely for general educational purposes and is not intended nor implied to be a medical diagnosis or treatment recommendation. This is not a substitute for professional medical advice relative to your specific medical condition or question. Always seek the advice of your own doctor for medical condition. Only your doctor can provide specific diagnoses and therapies.
if as described, do bone grafting the the outerside of the implant, if using patient's real bone: marrow which is taken from patient's knee, will that part of bone grafting will finally grow as patient's own bone and integrated with the implant? Thanks.