THE EFFECT OF LIGHT CURING GLASS IONOMER CONTAINING VARIOUS AMOUNTS OF ZINC OXIDE NANOPARTICLES ON THE STREPTOCOCCUS MUTANS ACTIVITY

BACKGROUND AND OBJECTIVE: Recently, one of the important titles in dentistry is usage of nanoparticles in improvement of antibacterial properties of resin composites. There are many interesting findings about the decrease in bacterial growth adding nanoparticles to resin composite. Since there are many interests to Nano Zinc Oxide as an antibacterial agent, in this study, we evaluated antibacterial effect of zinc oxide against streptococcus mutans. METHODS: In this in-vitro study, 30 samples in 2 microbiological test majors were evaluated (disc diffusion test and direct contact test). There were 5 groups of Resin Modified Glass Ionomer (RMGI) (Fuji II LC) containing different weight percent of Zinc Oxide (ZnO) nanoparticles (0, 1, 2, 3 and 5, respectively) and there were 3 samples in each group. These particles were mixed with RMGI powder by mortar and pestle in 20 minute after nanoparticles weighting by digital balance. For disc diffusion test, 15 discs of experimental GI were cured in 2mm A� 8mm plastic mold and their anti-streptococcus mutants effects were evaluated in agar culture. Antibacterial effects of 15 micro-tubes containing different groups of RMGI were evaluated in direct contact test. FINDINGS: In disc diffusion test there was significant increasing in non-growth halo of bacteria around the discs by increasing in nanoparticles percentage. In direct contact test there was no significant difference between 1, 2, and 3 weight percent groups but there was a significant difference between specimens containing 5 weight percent in comparison with control group. CONCLUSION: The results of this study showed a considerable decrease in bacterial growth with Nano ZnO weight percent increase. © 2014, Babol University of Medical Sciences. All rights reserved.