Inflamatory response of screw joint sealing agents used at the implant-abutment interface

Resumo

Adequate contact and passive fit between the components that form the implant-abutment interface promote greater screw joint stability in implant-supported prostheses. The maintenance of the preload is an indispensable mechanical factor for the stability of the complex. Objective: This study evaluated the rat subcutaneous tissue response to a commercial methacrylate-based sealing agent to be employed in the sealing of the implant-abutment interface of screw joints in implant-supported prostheses. Material and methods: Twenty-four male Wistar rats were submitted to the surgical procedure for insertion of polyethylene tubes into the subcutaneous tissue of the anterior region of the dorsum. On the right side the tube was implanted filled with the sealer and on the left side the tube was empty. After the experimental periods of 7, 15 and 30 days postoperatively, the animals were euthanized and the samples were dissected. The specimens were post-fixed, processed in a conventional manner and the histological sections were submitted to hematoxylin-eosin staining (HE) for histopathological analysis or to immunohistochemical processing to detect the main cytokines with proinflammatory activity: tumor necrosis factor-alpha (TNFα) and interleukin-1 beta (IL-1β) via immunolabeling density. Results: The magnitude of the local inflammatory response was similar between the control and the test site and underwent a gradual reduction over the experimental periods. There was no statistically significant difference in TNFα and IL-1β immunolabeling density between the control and the test site, except at 7 days postoperatively where the TNFα immunolabeling was greater at the test site when compared to the control site. There was a gradual reduction in the immunolabeling for both TNFα and IL-1β over the experimental periods. Conclusion: The m ethacrylate-based sealing agent showed a reduction in the inflammatory response throughout the experimental periods, which indicates that it may be employed as a sealing agent at the implant[1]abutment interface without resulting in undesirable tissue response in the adjacent tissues.