Biocompatibility and biomineralization of the experimental nanoparticulate mineral trioxide aggregate (MTA)

To investigate the tissue response and the biomineralization ability of the experimental nanoparticulate mineral trioxide aggregate compared to grey MTA and Fillapex MTA. Polyethylene tubes containing materials or empty tubes for control were inserted into the subcutaneous tissues of 30 rats. After 7, 15, 30, 60, and 90 days, the rats were killed and the tubes were removed for analysis using hematoxylin-eosin staining, von Kossa staining, and under polarized light. Inflammation was graded through a score system; the biomineralization ability was recorded as present or absent. The results were statistically analyzed using the Kruskal-Wallis test (p<0.05). On days 7 and 15 there was a significant difference between the Nano MTA (median score of 3) and MTA Fillapex groups (median score of 4), being MTA Fillapex the material with the highest number of inflammatory cells. At 30, 60, and 90 days there was no difference between the Nano MTA, Grey MTA, and MTA Fillapex groups. All materials induced the formation of mineralized tissue in all experimental periods. Nano MTA showed biocompatibility and biomineralization similar to grey MTA Angelus.