Antibacterial effect of glass ionomer cement containing metronidazole, ciprofloxacin, or penicillin V on Streptococcus mutans

Glass ionomer cement (GIC) is used in atraumatic restorative treatment, full crown cementation, and root lesion repair. Glass ionomer cement can prevent secondary infections if it has antibacterial properties. Therefore, in the current study, the antibacterial effects of GIC containing different antibiotics and the rate of antibiotic release were investigated.

In the in vitro study, GIC discs containing 1.5% metronidazole, ciprofloxacin, or penicillin V antibiotics were first made. Afterward, the amount of antibiotic release from different discs was analyzed by spectroscopic method at 24, 72, and 168 h. The antibacterial effects of GIC discs containing antibiotics were evaluated by the disc diffusion method against the standard bacterial strain of Streptococcus mutans and compared with standard antibiotic discs.

In the present study, antibiotic release from GIC discs containing penicillin could not be measured by spectroscopic method. Nevertheless, the rates of antibiotic release from GIC discs containing ciprofloxacin and metronidazole were about 41% and 66%, respectively in the first 24 h, and after 168 h, these release rates reached 53% and 75%, respectively. The results showed that GIC disc alone and GIC with metronidazole had no antibacterial effect on S. mutans. The mean scores of inhibition zone diameter of GIC discs containing penicillin and GIC containing ciprofloxacin were reported as 27.25±0.97 and 14.0±2.52 mm, respectively. Moreover, the GIC disc containing all three antibiotics had an inhibition zone diameter of 24.33±1.37 mm.

The inhibition zone diameter of penicillin was larger than that of the mixture of three antibiotics. Based on this observation, it can be concluded that the use of 1.5% penicillin is a more suitable choice for creating antibacterial properties in GIC compared to the mixture of three antibiotics.