Laser therapy in retrograde peri-implantitis. Case reports.

Background: The term retrograde peri-implantitis is commonly used to describe lesions in the periapical region of dental implant. It is defined as a clinically symptomatic periapical lesion ( diagnosed as radiolucency) that develops shortly after implant insertion while the coronal portion of the implant achieves a normal osseointegration. Etiologic factors that lead to retrograde peri-implantitis include, inter alia, the presence of a pre-existing inflammation. Information about the incidence and treatment of retrograde peri-implantitis is scarce and mostly collected from some sporadic case reports. The aim of this study is to compare manual debridement versus Er:YAG laser treatment as treatment modalities for retrograde preri-implantitis. Materials and methods: Two patients, that showed a radiolucency around the most apical part of the implant, were included in this study. Both patients were treated with a surgical procedure. The protocol included elevation of a full-thickness flap, complete removal of granulation tissue with hand instruments and curettage of the bony cavity walls. One of two patients also received treatment with Er:YAG laser. The patients were followed at 1 week, 1 month, 3 months, 6 months and 1 year postoperatively. Results: A 1-month follow-up, both two patients showed no pain or discomfort. No sign of infection was noted. A 3-months follow-up, the patient, who was treated only with manual debridement, showed a recurrence of the lesion while in the patient, who was treated with Er: YAG laser, was observed further progress of bone healing. The radiographic examinations of the patient who was treated with laser, at 6-months follow-up and at 1-year follow-up, showed increase radiographic bone density and new bone formation at the apical region of the implant. The patient remained asymptomatic. Discussion: The periapical lesion around the implants is a possible cause for implant failure. Quiryen and colleagues suggest that some of the early failures may be linked with an endodontic pathology remaining after tooth extraction. They also reported an almost three times higher incidence of failure for implants suffering from apical peri-implantitis when a endodontic pathology around previously extracted teeth was present. They also suggested that removal of all granulation tissue was sufficient to prevent further progression of the disease. This study instead shows that the addition of treatment with Er:YAG laser may decrease the risk of lesion recurrence.