Transforaminal and systemic diffusion of an active agent from a zinc oxide eugenol-based endodontic sealer containing hydrocortisone-in an in vivo model.

Objectives: This study aimed to quantify in vivo the release of hydrocortisone acetate (HCA) contained in a zinc oxide eugenol-based endodontic sealer, in various tissues.

Materials And Methods: Roots of human teeth, shaped with One Shape single file and sealed with Endomethasone N, previously radiolabelled with tritium (H-HCA), were implanted in the back of 24 mice. Mice were sacrificed at 2, 8, 24, and 48 h to evaluate and quantify the amount of radioactivity in subcutaneous tissues surrounding the apex (periapical-like) of the implanted teeth, blood, spleen, kidneys, liver, and urine.

Results: Radioactivity was released from the apex of the tooth into the periapical-like tissues with a peak measured at 2 h post-implantation (2.25% of the initial radioactivity/g). This quantity decreased significantly over time between 2 h and each time points. Radioactivity was still measured up to 48 h in the periapical-like tissues (0.42% of the initial radioactivity). The same pattern of kinetic was observed for all organs. The total quantity of radioactivity significantly decreased over time from 4.36% measured 2 h post-implantation to 0.74% at 48 h. Finally, about 10% of the initial radioactivity from Endomethasone N used to fill the root canal was retrieved after 48 h in the urine.

Conclusions: This study demonstrated that radioactive-HCA from Endomethasone N can diffuse through the apex of the root canal and follow a classical pharmacokinetics.

Clinical Relevance: This mouse model shows that radioactive-HCA can diffuse through the apex and do not accumulate in periapical-like tissues and organs.