Methods: The study groups were divided into 7 groups according to silver nanoparticles incorporation into GIC (Fuji IX™,GC corp, Japan) : 1%, 2%, 3%, 4%, 5%, 6%, and 7%(w/w), respectively. Glass ionomer cement and silver nanoparticle powder were used as control group. Three specimens of both control and study group were prepared as disc shape (5 mm in diameter) and placed on the agar plates inoculated with Streptococcus mutans at 37oC. The inhibition zone of each group was evaluated by measurement of the distance of the halo forming (outside the specimen) after 1day and 3 days. Data were analyzed using 1-way ANOVA with the LSD post hoc test (α=.05) and a pair T-test.
Results: All study groups showed the average inhibition zone ranged between 6.16 – 9.16 mm. The GIC specimen demonstrated no inhibition zone whereas the halo zone of AgN specimen is about 11.6 mm. There is an increase in inhibition zone when increasing the concentration of AgN but not significant different (p>0.05, 1-way ANOVA). However, it showed significantly different between 1% (w/w)-group and 7% (w/w)-group (p<0.05, 1-way ANOVA). There is no significant difference on the antibacterial properties of control group and study group after 1 day and 3 days evaluation (p>0.05, pair t test).
Conclusions: The present results demonstrate that experimental GICs containing silver nanoparticles are effective to inhibit bacteria growth associated with caries, and incorporation of 1% silver nanoparticles into GIC is optimal concentration to give appropriate properties.