Portland cement associated with niobium is evidenced by the presence of calcium crystals and biocompatibility in the rat subcutaneous tissue

This study evaluated the chemical, mechanical, and biocompatibility of Portland cement (PC) with different proportions of niobium oxide (Nb2O5). Five male Wistar rats were used. Four polyethylene tubes were placed on the dorsal subcutaneous tissue: one tube empty (NC), one tube MTA (Angelus®), one tube contained F6 (PC, Nb2O5 and CaSO4), and one tube F7 (PC, Bi2O3, Nb2O5 and CaSO4). After 60 days, animals were euthanized, and tubes were removed with the surrounding tissues. Inflammatory infiltrates were stained with hematoxylin–eosin. Mineralization was analyzed using Von Kossa staining and polarized light. The F6 showed small vessels and dispersed mononuclear inflammatory cells, score of 1 (1–2), p˃0.05 vs. NC 0.5 (0–1), and the absence of cell giants. Positive Von Kossa staining and birefringent structures under polarized light were observed with MTA, F6, and F7. The niobium oxide (Nb2O5), in association with Portland cement, exhibits calcium crystals and biocompatibility in rat subcutaneous tissue.