Antibacterial activity of glass-ionomer cement containing antibiotics on caries lesion microorganisms.

Purpose: To assess the total viable bacteria in infected dentin after sealing with glass-ionomer cement containing 1% metronidazole, 1% ciprofloxacin and 1% cefaclor.

Methods: 40 children were selected, with ages ranging from 4-10 years, with primary teeth with active carious lesions without any pulpal involvement. The patients were divided randomly into two groups in accordance to the glass-ionomer cement used to seal the carious lesions: Group 1 (control, n=20), sealing with conventional glass-ionomer cement; and Group 2 (test, n=20) sealing with glassionomer cement including antibiotics. The infected dentin was collected both before and 24 hours after the sealing of the cavities and, after inoculation in blood agar, all the plates were incubated in containers kept at 37 degrees C for 5 days in an atmosphere of 85% N2, 10% CO2 and 5% H2, for subsequent counting of total viable bacteria.

Results: The results were analyzed using the Wilcoxon and Mann-Whitney tests. The glass-ionomer cement with 1% of metronidazole, 1% of ciprofloxacin and 1% of cefaclor showed a significantly greater reduction in microbiota in the infected dentin in comparison to the reduction with the conventional ionomer cement (P< 0.01), with a mean reduction of 98.65% of all viable bacteria. The infected dentin after sealing with glass-ionomer cement with antibiotics showed, using scanning electron microscopy, the presence of bacterial aggregates, intertubular dentin with exposure of collagen fibers, and dentin tubules.