I'll be getting implant's over the next couple of months. I need the front 4 teeth replaced with either 4 separate implants of a 4 unit bridge on 2 implants. I'm very excited, but I'm frightened of peri-implantitis! I figure that if I go the 4 unit bridge on only 2 implants and gum disease strikes. then it'll spare half the area, thus leaving it to use later, especially if I require gum grafts? Could someone please give me their opinion?