Antibacterial activity of two Mineral Trioxide Aggregate materials in vitro evaluation

It has been documented that total removal of carious dentin, assessed according to clinical criteria, does not mean complete eradication of bacteria. For that reason in prevention of caries and pulp inflammations, application of the materials having high antibacterial properties seems to be indispensable.

Determination of antibacterial activities of two white Mineral Trioxide Aggregate (MTA) preparations against bacteria of the genus Streptococcus.

Antibacterial activities of the materials were determined by diffusion method on a solid tryptic-soy medium (Tryptic Soy Agar, Oxoid). Wells were prepared on the medium with a puncher of 7 mm diameter and 5 mm depth (four for each material). The bottom was poured with 10 microlitres of liquid TSA for sealing. Bacterial suspension was inoculated with cotton swabs onto the medium surface and then the wells were filled with the materials prepared ex tempore. The plates were left in room temperature for 30 minutes and incubated at 37 degrees C for 24 h. Results were read by measuring the inhibition zones on day 1, 2, 3 and 8 of the culture.

All the study samples demonstrated inhibition of bacteria of the genus Streptococcus. The antibacterial effect of MTA was maintained till the end of the experiment (day 8). ProRoot White showed slightly larger inhibition zone against Streptococcus salivarius and Streptococcus sanguis as compared to MTA white Angelus. The mean inhibition zones against Streptococcus mutans appeared the same for both test materials.

The two MTA preparations assessed in the current study show good antibacterial action against the standard strains Streptococcus mutans, Streptococcus sanguis and Streptococcus salivarius.