An unusual case report of peri-implant cystic lesion.

A new entity called "peri-implant cyst" has recently been described. This lesion is an inflammatory odontogenic cyst on an osseointegrated implant. It arises from inflammatory stimulation and proliferation of the rests of Malassez. Although a relatively rare condition but potentially the cause of implant failure. Peri- implant cystic lesion exhibits the same radiographic and histopathological features as the radicular cyst. The diagnosis rests on the histology, radiology, and on their correlation with clinical features, in particular the location of the lesion. Herein, we report a case of a 58-year-old female diagnosed as peri-implant cyst in the periapical area of the right maxillary first premolar implant. The microscopic examination revealed a cystic lining composed of non-keratinized stratified squamous epithelium covered with multilayered epithelium. The lesion was surgically enucleated along with preservation of the implant and wit guided bone regeneration (GBR) method, without any postoperative complications and satisfactory healing, was achieved. One year later, a newly formed bone at the apical region of the right maxillary first premolar implant was radiologically observed.