Histopathological Insights into Peri-Implant Mucosal Inflammation: Comparative Analysis of Peri-Implant Mucositis and Peri-Implantitis as Distinct Disease Entities with Emphasis on Foreign Body Reactions

Peri-implant diseases, including peri-implant mucositis and peri-implantitis, constitute significant human health challenges that threaten implant longevity despite advances in implant medicine. These inflammatory disease entities compromise peri-implant tissue integrity and oral wellbeing, with growing public health relevance due to the widespread use of dental implants. Increasing evidence implicates tribocorrosion-induced titanium particle release in provoking foreign body-mediated inflammation, facilitating disease progression from a reversible inflammatory illness to an irreversible destructive condition. This study aimed to compare the histopathological characteristics of peri-implant mucositis and peri-implantitis. Fifty systemically healthy individuals with titanium implants in function for approximately one year were enrolled and categorized into two groups-peri-implant mucositis (n = 25) and peri-implantitis (n = 25), based on clinical and radiographic criteria. Peri-implant mucosal biopsies were obtained and stained with hematoxylin and eosin for histopathological evaluation. Parameters including epithelial morphology, inflammatory cell infiltrate, fibroblast distribution, vascularity, and evidence of foreign material or giant cell response were assessed. Peri-implant mucositis demonstrated parakeratinized stratified squamous epithelium with epithelial downgrowth and chronic inflammatory infiltrates of lymphocytes and plasma cells. Conversely, peri-implantitis revealed dense mixed inflammatory infiltrates with neutrophils, macrophages, and multinucleated giant cells encircling amorphous eosinophilic debris suggestive of metallic particles, indicative of a foreign body-type reaction. Distinct histopathological patterns differentiate peri-implant mucositis from peri-implantitis. The presence of foreign material and multinucleated giant cells in peri-implantitis underscores the potential role of tribocorrosion and titanium particle release in its pathogenesis. Early identification and preventive management are vital for maintaining peri-implant health.