About a year and a half ago I had an implant done on my front tooth and never had any problems with it. It doesn't hurt and its not loose, but now it is infected somewhere and they gave me antibiotics. What treatment comes next? Is the implant failing? Will it have to be removed?
The next step in treatment is possibly a bone graft to add bone to the area where the infection took bone away (a procedure called Guided Bone Regeneration). Get a 2nd opinion from a periodontist or oral surgeon who can more definitively diagnose what the problems is and give you a treatment plan. It may be failing but it also may be able to be salvaged at this point. This is sometimes difficult to do.
A front tooth is nothing to mess around with. You should definitively treat it as soon as possible to give you the best chance to potentially salvage the implant. The end point for a failing implant is indeed mobility or movement. Once it is moving it must be taken out.
There are other parts involved thought that may ultimately be moving: the abutment or the crown upon the implant. Front teeth are tricky though because even if the implant is not mobile, bone loss can result in gum loss leaving an esthetic nightmare.
Get a 2nd opinion and treat aggressively and definitively as possible. Rarely will antibiotic treatment solve the problem. You also need to be certain an adjacent tooth is not the culprit!