B. lactis HN019 modulates periapical inflammation and enhances cementum repair by increasing CEMP-1 expression in an animal model.

Abstract

OBJECTIVE: To investigate the effect of the HN019 probiotic on the modulation of inflammation and the resorption of mineralized tissues in experimentally induced periapical lesions in an animal model, evaluating its impact on the expression of cementum protein 1 (CEMP-1). DESIGN: Periapical lesion was induced in 45 Wistar rats. The animals were divided into groups according to the irrigating solution used. Root canals were irrigated on days 7 and 14. After 21 days, the animals were euthanized, and mandibles were processed for histological analysis. Descriptive and semi-quantitative evaluations of the inflammatory infiltrate, periodontal ligament, bone and cementum resorption, as well as counts of inflammatory cells were performed using HE staining. Also, to assess cementum formation, tissue sections were stained with an antibody for CEMP-1 and analyzed by immunohistochemistry. RESULTS: In the Infection +&#x202f;Probiotic Group, the inflammatory infiltrate was mixed and diffuse, ranging from mild to severe, with no statistically significant difference compared to the Control Group (p&#x202f;>&#x202f;0.05). However, in the Infection +&#x202f;Probiotic Group, cementum resorption was significantly lower compared to Control Group (p&#x202f;<&#x202f;0.001). Moreover, CEMP-1 expression was significantly higher in Infection +&#x202f;Probiotic-Group compared with all other groups (p&#x202f;<&#x202f;0.0001). CONCLUSION: The probiotic HN019 significantly increased CEMP-1 expression, indicating cementum formation in periapical lesions in vivo. These findings suggest that B. lactis HN019 may have regenerative potential in clinical scenarios. Furthermore, this strain appears to modulate the inflammatory state of periapical lesions toward a reparative phenotype, characterized by reduced bone resorption. Also, inflammatory infiltrate was like control group.