MTA preparations from different origins may vary in their antimicrobial activity.
OBJECTIVE
The antimicrobial effects of 4 mineral trioxide aggregate (MTA) preparations, 2 white-colored (WMTA-1, WMTA-2) and 2 gray-colored (GMTA-1, GMTA-2), against C. albicans and E. faecalis were assessed in vitro.


METHODS
Minimal inhibitory concentration (MIC) for each preparation was determined using the tube dilution test and Sabouraud agar media for C. albicans and brain heart infusion media for E. faecalis. Broth tubes were prepared and divided into experimental and control groups. Aliquots of each of the tested microorganisms were taken from a stock culture and added to each experimental and positive control group. All groups were incubated at 37 degrees C and evaluated for turbidity at 24-, 48-, and 72-hour time periods. Samples of 0.1 mL from each of the experimental and control tubes were subcultured on agar or brain heart infusion plates to confirm visible signs of bacterial or fungal growth.


RESULTS
MIC of MTA against the 2 microorganisms tested varied among the 4 preparations tested. WMTA-1 and WMTA-2 inhibited C. albicans growth at concentrations of 3.125 mg/10 mL and 25 mg/10 mL, respectively, and statistically significant differences were found between WMTA-1 and WMTA-2 (P < .001). WMTA-1 and WMTA-2 inhibited E. faecalis growth at concentrations of 12.5 mg/10 mL and 50 mg/10 mL, respectively, and statistically significant differences were found between WMTA-1 and WMTA-2 (P < .001). GMTA-1 and GMTA-2 inhibited E. faecalis growth at concentrations of 12.5 mg/10 mL and 3.125 mg/10 mL, respectively, and statistically significant differences were found between GMTA-1 and GMTA-2 (P < .001). Both GMTA-1 and GMTA-2 inhibited C. albicans growth at a concentration of 3.125 mg/10 mL and no statistical differences were found between the preparations. Subculture of the broth tubes in agar or brain heart infusion plates confirmed the turbidity test result.


CONCLUSIONS
The origin of MTA as well as the type of preparation may affect its antimicrobial characteristics. Clinicians should be aware of variations that may exist among such MTA preparations.
King Saud University, College of Dentistry, Riyadh, Saudi Arabia. alhezaim@usc.edu
Khalid
K
Al-Hezaimi
Thakib A
TA
Al-Shalan
Jafar
J
Naghshbandi
James H S
JH
Simon
Ilan
I
Rotstein
D017607:Aluminum Compounds / Q000737:chemistry / Q000494:pharmacology*; D017610:Calcium Compounds / Q000737:chemistry / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects*; D015169:Colony Count, Microbial; D004338:Drug Combinations; D013293:Enterococcus faecalis / Q000187:drug effects*; D005602:France; D005858:Germany; D008826:Microbial Sensitivity Tests; D010087:Oxides / Q000737:chemistry / Q000494:pharmacology*; D012387:Root Canal Filling Materials / Q000737:chemistry / Q000494:pharmacology*; D017640:Silicates / Q000737:chemistry / Q000494:pharmacology*
D017607:Aluminum Compounds; D017610:Calcium Compounds; D004338:Drug Combinations; D010087:Oxides; D012387:Root Canal Filling Materials; D017640:Silicates; C086631:mineral trioxide aggregate