Avaliação da mucosa periimplantar em pacientes com periimplantite: aspectos clínicos, histopatológicos e imunológicos

Abstract

The periimplantitis is a lesion surrounding dental implants due to factors such as excessive mechanical stress, corrosion and aggressive bacteria, which can cause infection and inflammation, and bone loss around dental implants. Objective – The aim of this study was to compare the inflammatory response in peri-implant gingival tissue between the group of patients with peri-implantitis (PP) and group with healthy healthy peri-implant tissues (HP). Material e Methods – Biopsy was performed of peri-implant mucosa of 18 patients: nine of PP group and nine of HP group. In each case two fragments were collected and serial sections were performed for histological and immunohistochemical analysis. One of the fragments was collected for the histopathological analysis, with use of hematoxylin-eosin (HE) and picro-sírius to quantify the density of inflammatory cells and collagen fibers respectively. Immunohistochemical analysis was performed to TGF-β, IL-17, CD31, mast cell chymase, and mast cell tryptase. The other fragment was used to quantify the expression of IL-13 by Enzymatic Immunoabsorbent Assay (ELISA). Results – Immunostained cell density for TGF-β, IL-17 and CD31 was significantly higher in PP group when compared with HP group. PP group showed greater density of red cells, leukocytes, mast cells chymase and mast cell tryptase, however, without significant difference.HP group patients showed higher IL-13 expression and increased amount of collagen fibers when compared with PP group patients, with significant difference. None of the patients presented suppuration or necrosis. There was significant positive correlation between the mast cell tryptase density and density of blood vessels immunostained with anti-CD31 in the PP group. There was significant positive correlation between the mast cell chymase density and density of blood vessels immunostained with anti-CD31 in the PP group. There was significant negative correlation between the density of IL-17 and collagen. Conclusions - This study demonstrated that in patients with peri-implantitis there was an increase in TGF-β and IL-17, indicating that these cytokines are directly involved in the inflammatory process. In addition, it demonstrated that there was an increase in IL-13 in patients with health peri-implant tissues, which could explain the larger number of collagen fibers in this group, suggesting that this cytokine has anti-nflammatory action. Thus, understanding the influence of cytokines in the peri-implantitis installation, new therapies could be developed in order to inhibit the synthesis of IL-17 and induce synthesis of IL-13 in peri-implant tissue, contributing to increase the longevity of the implant.