I have had to have the top left first molar removed( called #12 molar in Canada). It was removed last month and has healed. I am nervous about the sinus cavity and nerves being hit in an implant procedure, and wonder what will happen if the empty space is just left. Do I really need an implant? I am 60 years old. Will the back two molars shift towards the front? Will the front two teeth, start to have gaps?