Evaluation of the radiopacity and cytotoxicity of Portland cements containing bismuth oxide

Objective. This study aimed at evaluating the radiopacity and cytotoxicity of Portland cements containing bismuth oxide (PcBo) in varying ratios. Study design. Specimens measuring 10 mm in diameter and 1 mm in thickness were radiographed with an aluminum step wedge using an occlusal film. The radiographs were digitized, and the radiopacity of each material was compared to the different thicknesses of the aluminum step wedge. Using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, the cytotoxicity of each material was determined in immortalized human periodontal ligament (IPDL) cells. Results. The results demonstrated that Portland cement with 20% bismuth oxide presented greater radiopacity (P <.05) compared to the mixtures with less bismuth oxide. The cell viabilities of all PcBo groups were statistically similar (P >.05) throughout the experimental period. Conclusion. These results indicate that Portland cement with 20% bismuth oxide has a greater potential for being used as a root-end filling material compared to Portland cement with less bismuth oxide.