Metronidazole-loaded glass ionomer dental cements

The incorporation of antibiotics in glass ionomer cements (GICs) for the treatment of periodontal diseases has been considered as an effective therapeutic strategy. In this research, metronidazole was added to silanized glass fiber-reinforced GICs. The fiber-reinforced cements containing antibiotic were made by adding 6.0 w% silanized E-glass fibers and 3.0 w% metronidazole to the GIC powder. The GIC reinforced with 6.0 w% silanized fibers showed maximum values of 57 MPa, 2.1 GPa, and 1.3 MPa‧m^0.5 for the flexural strength, flexural modulus, and fracture toughness, respectively. The release of metronidazole showed a two-step release in which about 65% of total amount was released in the first 24 hours. Antibacterial test exhibited no bacteria number (CFU/mL) in the presence of GIC containing metronidazole. In addition, gene expression of Streptococcus mutans was performed by real-time PCR method. Based on PCR results, metronidazole significantly reduced the gtfB and gtfC genes expression, related to adherence and biofilm formation, up to 98% after 7 days in comparison to the control one (P < .001). According to the obtained results, GICs reinforced with silanized fibers containing metronidazole are effective in inhibiting bacteria associated with caries and also acceptable mechanical properties for the development of the next generation of restoration dental materials.