Patient came with #9 fractured at gum line, not infected. Atraumatically removed #9 and placed Nobel 4.3 x 13-mm Active implant with 5 x 5 yellow healing abutment. The root of #9 was also approximately 13 mm. I torqued the implant to 35 Ncm. Facial bone was intact, but thin. Approximately 1.5 mm of dead space between implant and facial bone which I filled in with cortical/cancellous mix of donor bone. I did not put the patient on antibiotics. Gave patient an Essix appliance to wear when necessary. The patient stated he wore it little as it did not fit well. First week looked good. Patient came back three weeks after implant placement; there was pus and bone loss all around #9. Why did this happen?