No abstract

The antimicrobial activity of Grossman's sealer and its components was evaluated on 13 different strains using the double layer well-diffusion method. Results revealed that Grossman's sealer presented antimicrobial activity against all the tested strains. Among the components of the cement, sodium tetraborate presented the greatest antimicrobial activity, both in type and diameter of the halo and ring of inhibition. Sealer powder, rosin, and eugenol presented similar activity, with no effect on P. aeruginosa and C. albicans. Among these, only eugenol had an effect on E. coli. Zinc oxide was only active against S. sobrinus and E. coli. Barium sulfate and bismuth subcarbonate did not show any antimicrobial effect.

A study was conducted on the hardening time of three Grossman's cements with different powder particle sizes (60, 100 and 150 mesh) using Specification n. 57 of the AMERICAN DENTAL ASSOCIATION1 (1983). The cement obtained from mesh 150 particles showed the longest hardening time (22 minutes), which was different when compared to mesh 60 (17 minutes) and 100 (17 minutes) particles.

Proposition: To evaluate the physical properties of flow and solubility of pure and improved mineral trioxide aggregate (MTA) cement with the addition of two plasticizing agents: sodium ether polycarboxylate and sodium naphthalene sulfonate at three different concentrations. Material and Methods: Flow and solubility tests were carried out using the established methodology recommended by the 57 ANSI/ADA and ISO 6876:2012 standards. Pure MTA was used as control group and was compared to the MTA containing sodium ether polycarboxylate and sodium naphthalene sulfonate at concentrations of 0.5%, 1.0% and 1.5%. Data were analyzed by one-way analysis of variance followed by a post-hoc Tukey test at a 5% significance level. Results: Sodium ether polycarboxylate increased the MTA flow at the three concentrations. The flow increased with increasing concentration (P<0.05). Sodium sulfonate naphthalene also facilitated flow, though it was inferior to sodium ether polycarboxylate. Sodium naphthalene sulfonate promoted a significant increase in the solubility of MTA (p=0.000). Conclusions: The additives improved the physical properties of MTA. Sodium ether polycarboxylate was found to be superior to sodium naphthalene sulfonate at all concentrations.