Method: MTA was prepared following the manufactuers' instructions in sterile condition and allowed to set in 24-well -culture-dish for 4 or 24 h with 100% relative humidity. 4×106/ml human neutrophils were seeded on MTA for 4 h at 37oC. Specimens were examined by scanning electron microscope. In addition, the effects of MTA on the chemotactic ability were examined using transwell migration assay.
Result: Under the scanning electron microscopy, MTA seemed to be biocompatible with the neutrophils. No obvious difference was observed between cells seeded on MTA and the control group. However, freshly prepared MTA or MTA set for 4 h reduced the migration ability of neutrophils. In contrast, MTA set for 24 h did not alter the chemotaxis of neutrophils.
Conclusion: The results showed that although MTA displayed good biocompatibility, non-setting MTA might reduce the immune functions of the neutrophils.