Comparison of antibacterial effects of orthodontic composites containing different nanoparticles on Streptococcus mutans at different times

Abstract

Introduction: Plaque accumulation can cause white spot lesions. Adding nanoparticles to composites can be effective in reducing the number and function of microorganisms. Objective: The aim of this study was to evaluate the antibacterial effects of orthodontic composites containing different nanoparticles on Streptococcus mutans at different times. Methods: Hydroxyapatite, titanium oxides, zinc oxide, copper oxide and silver oxide nanoparticles were prepared at 0.5% and 1% weight concentrations. Accordingly, ten study groups and one control group were obtained. Then, 26 composite discs were prepared from each group. Strain of Streptococcus mutans was cultured, and colonies of Streptococcus mutans were counted. Further bacterial culture was swapped onto enriched Mueller-Hinton agar. The composites were placed on the culture medium, and after incubation the diameter of growth inhibition was measured. To investigate the long-term effect of nanoparticles, the colonies were counted at days 3, 15 and 30. Results: The results showed that 1% copper oxide and 1% silver oxide significantly reduced the number of bacteria (p< 0.05), but there was no significant difference between the other groups and control group (p> 0.05). At day three, there was a significant difference between control group and 0.5% silver oxide, 1% silver oxide and 1% copper oxide groups (p< 0.05). However, colonies had grown in all groups at day 30 but showed no significant difference with control group (p> 0.05). Conclusion: Addition of 1% copper oxide and 1% silver oxide has short-term antibacterial effects, so the clinical use of these nanoparticles cannot be justified.

Evaluation of the Shear Bond Strength and Antibacterial Activity of Orthodontic Adhesive Containing Silver Nanoparticle, an In-Vitro Study

“…We used 0.3% weight concentrations of AgNPs and measured the diameter of growth inhibition at 24 h and 30 days observing significant antibacterial effect at both time points. Previous studies confirmed that orthodontic adhesive with AgNPs were effective against Streptococcus mutans [ 34 , 35 ]; however, some did not report the same effect after 30 days. For 0.5% and 1% weight concentrations [ 34 ], although there was difference in the diameter of growth inhibition at 24 h, the same effect was not observed at 30 days.…”

“…Previous studies confirmed that orthodontic adhesive with AgNPs were effective against Streptococcus mutans [ 34 , 35 ]; however, some did not report the same effect after 30 days. For 0.5% and 1% weight concentrations [ 34 ], although there was difference in the diameter of growth inhibition at 24 h, the same effect was not observed at 30 days. Therefore, authors suggested a short-term antibacterial effect for AgNPs [ 34 ].…”

“…For 0.5% and 1% weight concentrations [ 34 ], although there was difference in the diameter of growth inhibition at 24 h, the same effect was not observed at 30 days. Therefore, authors suggested a short-term antibacterial effect for AgNPs [ 34 ]. The concentration used in the present study (0.3% weight) was lower and differences in methodology may explain the different outcome at 30 days.…”

Creating Antibacterial Properties in Flowable Dental Composites by Incorporation of 3,4-dihydropyrimidin-2(1H)-ones

“…Yassei et al [50] used copper oxide nanoparticles to create antibacterial properties in dental composites. Although this compound had an antibacterial effect in the composites, it reduced the depth of cure but used the 3,4-dihydropyrimidin-2 (1H) -ones did not show a significant difference in depth of cure.…”

Nanomaterials Application in Orthodontics

“…It was proved by Yassaei et al [ 70 ], that no significant difference was found between silver and copper oxide (CuO) nanoparticles, but it was noted that a curing time increased with the use of copper material when compared to the silver one. The former is cheaper and additionally both physically and chemically more stable than the latter.…”