Implant has shifted - how should I proceed?

I got an implant placed2 years ago, about a year into the implant o noticed it shifted forward a bit. Thw dc.that placed it has since left. So i went to an oral surgon, and he said it might be a failed implant but to go see another dc.(dc #2) he evaluated the implant and i dont have any painful areas when touching, he said its a little mobile, but i dont notice it being mobile. *note its my front tooth #9. Its a deep implant. I didt have a lot of bone. On the exray they say i have very little bone too. A diffrent dc.reccommed for me to get bone and gum grafting done. Anyway back to dc#2, he said he had years of experiance, yet couldnt tell me what might cause the shift. But he had the oral surgon would talk. They called me today and said they think it might be a none stable implant, and that i should abondan it. Note* i have no pain/swelling/bleeding or anything. My gum is recedded, but not to the poiny where you can see the metal piece or anything. I dont want to get it removed if not neccasry. What shoild i do. *Ive always had an off bite, but my bouttom teeth do not touch the implant ever.