Six months after implant placement to restore a maxillary lateral incisor, a 55-year-old patient developed a sinus tract associated with the apical area. Radiographic examination revealed a periapical radiolucency at the apex of the implant, and a diagnosis of retrograde peri-implantitis was made. Treatment consisted of elevation of a full-thickness flap, curettage of the apical lesion, irrigation with chlorhexidine gluconate, placement of demineralized freeze-dried bone, and coverage of the site with an absorbable collagen would dressing before primary closure of the flap. The prosthesis is functioning satisfactorily 17 months after apical treatment was performed.