Clinical and histological healing pattern of peri-implantitis lesions following non-surgical treatment with an Er:YAG laser

Background and Objectives: The aim of the present study was to assess clinical and histo-pathological healing pattern of peri-implantitis lesions following non-surgical treatment with an Er:YAG laser (ERL). Study Design/Materials and Methods: Twelve patients suffering from peri-implantitis (n = 12 implants) received a single episode of non-surgical instrumentation using ERL (12.7 J/cm(2)). Assessment of clinical parameters (plaque index (PI), bleeding on probing (BOP), probing pocket depth, gingival recession (GR), and clinical attachment level (CAL)), surgical defect examination, and histopathological examination of peri-implant tissue biopsies was performed after 1, 3, 6, 9, 12, and 24 months. Results: All patients exhibited improvements of all clinical parameters investigated. However, histo-pathological examination of tissue biopsies revealed a mixed chronic inflammatory cell infiltrate (macrophages, lymphocytes, and plasma cells) which seemed to be encapsulated by deposition of irregular bundles of fibrous connective tissue showing increased proliferation of vascular structures. Conclusion: It was concluded that a single course of nonsurgical treatment of peri-implantitis using ERL may not be sufficient for the maintenance of failing implants.