Odontoblast-like Cell Response to Calcium Aluminate Cement With Additives

Objectives: This study aimed to evaluate the effects of calcium chloride (CaCl₂) and bismuth oxide (Bi₂O₃) additives in odontoblast cell response to calcium aluminate cement (CAC), comparatively to the gold standard mineral trioxide aggregate (MTA).
Methods: Odontoblast-like cells form MDPC-23 cell line were grown overnight and then exposed for periods of up to 14 days to samples of: 1) CAC with 2,8% CaCl₂ and 25% ZnO (CACz), 2) CAC with 2,8% CaCl₂ and 25% Bi₂O₃ (CACb), 3) CAC with 10% CaCl₂ and 25% Bi₂O₃ (CACb+) or 4) MTA, placed on inserts. Cultures grown in the absence of cements served as control. Cell morphology and cell viability were evaluated at days 1 and 3 by epifluorescence and mitochondrial tetrazolium test (MTT), respectivelly; in situ alkaline phosphatase (ALP) activity was assessed at day 7 by Fast red; matrix mineralization was evaluated at day 14 by alizarin red staining. Data was compared using ANOVA test (α=5%).
Results: Lower cell density and cell spreading was observed in cultures exposed to cements, particularly in the MTA and CACb+. Cell viability raised over time for all groups and was similar among groups on days 1 and 3 (p < 0.05), but lower cell viability was observed for MTA and CACb+ at day 7 (p < 0.05). All cements supported ALP activity, but CACb inhibit matrix mineralization (p < 0.05).
Conclusions: In conclusion, the replacement of zinc oxide by bismuth oxide on CAC results in lower cell differentiation in odontoblast-like cells, while the association of bismuth oxide with a higher concentration of calcium chloride in CAC reverted the negative effects of bismuth oxide. Thus, these additives together make CAC a promising alternative to the MTA for the regenerative procedure of the dentin-pulp complex.