Collagen quantification in peri-implant soft tissues in human peri-implantitis lesions

Peri-implantitis is an inflammatory lesion of bacterial etiology characterized by inflammation of the mucosa and bone loss. Chronic inflammation is characterized by neovascularization and collagen neoformation. Mast cells have been shown to participate in the inflammatory process by releasing mediators and proteases such as chymase and tryptase, important in the collagen neoformation process. Although a higher percentage of collagen has been described in periodontal disease, the literature is scarce about the percentage of collagen in peri-implantitis. The aim of this study was to quantify the percentage of collagen fibers present in the peri-implant soft tissue of patients with peri-implantitis lesions. A descriptive observational cross-sectional study was performed. Samples of peri-implant soft tissue were collected from eleven patients with peri-implantitis and then processed by Masson's Trichrome Technique. In microscopic analysis, collagen fibers were observed in all samples, with an average percentage of 39.89 %, standard deviation of 17.02 %, with a minimum value of 8.99 % and a maximum value of 75.65 % density. From these results, it can be concluded that in human peri-implantitis lesions with bone loss greater than 50 %, there is an important percentage of collagen fibers, which is interpreted as connective tissue in a permanent process of reparative response, in the presence of inflammatory infiltrate.