Imunoexpressão de MMP-2, MMP-9 e IL-1 em cistos radiculares e granulomas periapicais

Abstract

Periapical granulomas and radicular cysts are common lesions involving the tooth-supporting tissues, resulting from pulp necrosis. They are mostly caused by microorganisms following the disruption of a tooth's external surface, exposing dentin, allowing intracanal microbiota irritants to transit to the periapex, where an initial inflammatory reaction is triggered to prevent the spread of the infectious process to the alveolar bone. Defense mechanisms include inflammatory and resorptive events, involving proteins that play a significant role in bone resorption, such as interleukins and matrix metalloproteinases. These processes highlight the expression of the pro-inflammatory cytokine (IL-1) in macrophages and other cells, in addition to matrix metalloproteinase-9 (MMP-9) and matrix metalloproteinase-2 (MMP-2), enzymes that are vital in physiological processes like tissue morphogenesis, repair, remodeling, and wound healing, but are also involved in extracellular matrix remodeling and maintenance of periapical lesions. In this context, this study aimed to semiquantitatively evaluate the immunoexpression of IL-1, MMP-2, and MMP-9, aiming to correlate them with clinicalradiographic profiles, measuring lesion area, perimeter, and their major diameters in mesiodistal and superoinferior dimensions, as well as bone remodeling in periapical lesions. The sample consisted of 26 RCs and 8 GPs, and the lesions were categorized into groups distinguished by the presence or absence of a radiopaque halo. The results demonstrated a statistically significant difference in the correlation of IL-1 and MMP-9 immunoexpression scores in the group with a sclerotic halo present (p = 0.009), but not among lesions without the halo (p = 0.080). Furthermore, although there was no statistically significant association when individually relating each biomarker to the studied lesions, IL-1 immunoexpression in lesions with a larger area (>153 mm²) was indicated by the mean ranks (p = 0.063). Thus, it is suggested that IL-1 and MMP-9 participate in the maintenance of periapical lesions with a sclerotic halo through bone remodeling, contributing to persistent inflammation and bone resorption.