In vivo long-term effects of bioactive mineral trioxide aggregate on the inflammatory response and repair in dental pulp.

The goal of this study was to evaluate, in vivo, the synthesis of inflammatory and repair mediators in dental pulp after capping with a reparative bioactive material. Pulp capping was performed with mineral trioxide aggregate (n = 20) and gutta-percha (n = 10) on mandibular first molars of C57Bl6 mice. After 7 and 70 days, tissues were stained with hematoxylin and eosin for histopathological, histometric, and immunohistochemical evaluation to investigate the synthesis of ALP, IL-1β, IL-4, IL-6, PECAM-1, and VEGF. Data regarding measurement of the area of newly formed mineralized tissue, number of inflammatory cells in dental pulp, and intensity of immunostaining were compared using Student's t-test at a significance level of 5%. At 7 days, an inflammatory response was found in contact with MTA and gutta-percha, while at 70 days, inflamation was reduced in both groups. However, mineralized tissue formation was observed only with MTA. IL-1β, VEGF, and PECAM-1 were detected in cells in close contact with MTA at 7 days, which reduced overtime. On the other hand, synthesis of ALP, IL-4, and IL-6 was mild at 7 and 70 days without difference between the periods. Mineralized tissue formation was observed only with MTA. IL-1β, VEGF, and PECAM-1 were synthesized by dental pulp and inflammatory cells in close contact with the material, whereas IL-4, IL-6, and ALP synthesis were scarcely found. Understanding the molecular and cellular responses elicited by MTA can enhance the development of more effective treatments, potentially leading to improved long-term outcomes for patients with dental pulp injuries or diseases.