Osteogenic cell response to calcium aluminate-based cement

To evaluate the effect of a calcium aluminate-based cement (CAC+) on the development of the osteogenic phenotype in vitro.

Rat calvaria-derived cells were grown on Thermanox^® coverslips for 24 h and then exposed to either samples (4-h set) of CAC+ or mineral trioxide aggregate (MTA) placed on Transwell^® inserts for periods of up to 14 days. Nonexposed cultures were used as the controls. The comparisons were made using the nonparametric Kruskal-Wallis test, followed by the Student-Newman-Keuls post hoc test when appropriate.

The results showed that proximity to MTA or CAC+ samples inhibited cell growth, whereas at a distance, viable and proliferative cells adhered to and spread on the Thermanox^® , expressing osteoblast differentiation markers prior to mineralization of the extracellular matrix. Compared with MTA, the osteogenic cell cultures exposed to CAC+ exhibited significantly greater cell viability, alkaline phosphatase (ALP) activity and expression of runt-related transcription factor 2, osterix, ALP, bone sialoprotein and osteocalcin (P < 0.05 for all). For the osteogenic cell cultures exposed to CAC+, the quantification of matrix mineralization was not altered (P > 0.05).

CAC+ supported the acquisition of the osteogenic cell phenotype in vitro, rendering this novel material a potential alternative to MTA in endodontic procedures. Further in vivo studies are needed to verify if the beneficial in vitro effects of CAC+ on osteoblastic cells correspond to an increase and/or acceleration of bone repair in the periapical region.