Journal of Medical Bacteriology 2013. 2(3-4):1-10.

Antimicrobial Effect of Nano-Zinc Oxide and Nano-Chitosan Particles in Dental Composite Used in Orthodontics
AmirHossein Mirhashemi, Abbas Bahador, MohammadZaman Kassaee, Ghazaleh Daryakenari, MohammadSadegh Ahmad-Akhoundi, Ahmad Sodagar


Background: Incidence of  white  spots due  to  demineralization of  enamel  and  gingival problems  is  an  unacceptable  result  of  orthodontic  treatment.  Plaque  accumulation  and bacterial biofilm growth are responsible for these phenomena. The resin-based dental composites used as bonding agents in orthodontics play a major role in mentioned problems. As recent researches assert the antimicrobial effects of chitosan (CS) and zinc oxide (ZnO) nanoparticles  (NPs),  it  seems  that  adding  these  nanoparticles  to  the  composite  can  be beneficial in reducing the number and function of microorganisms. The aim of this study was to  evaluate  the  antimicrobial  effects  of  ZnO-NP  and  CS-NP-containing  orthodontic composite.
Methods: Antibacterial effectiveness of ZnO-NPs and CS-NPs was assessed in four groups against Streptococcus mutans, Streptococcus sanguis and Lactobacillus acidophilus grown both planktonic and as a biofilm on composites. One group as the unmodified control group and  three  groups  consisting  of  three  different  concentrations of  ZnO-NPs  and  CS-NPs mixture: 1%, 5% and 10% (1:1 w/w). 108 CFU/ml microorganism suspensions were provided with spectrophotometer. Biofilm formation was quantified by viable counts. Disc agar diffusion (DAD) test was carried out to determine antimicrobial effects of nanoparticles by measuring the inhibition diameter on brain heart infusion agar plates. Finally,viable counts of microorganisms on days 3, 15 and 30 were collected for the antimicrobial effects of eluted components from composite discs.
Results: In biofilm formation test, a reduction in bacterial counts was observed with 10% nanoparticle-containing composites compared with their unmodified counterpart. In the DAD test only 10% nanoparticle-containing specimens showed statistically significant inhibition. The only noticeable datain eluted component test was on day 30 for 10% nanoparticle- containing discs, inhibiting L. acidophilus.
Conclusion: It seems that a mixture of ZnO-NPs and CS-NPs has induced an antibacterial activity in resin composite; especially in 10% weight concentrations which was significantly higher than other groups.


Chitosan, Zinc Oxide, Orthodontics

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Zalkind MM, Keisar O, Ever-Hadani P, et al. Accumulation of Streptococcus mutans on light-cured composites and amalgam: an in vitro study. J Esthet Dent 1998; 10 (4): 187-90.

Beyth N, Houri-Haddad Y, Baraness- Hadar L, et al. Surface antimicrobial activity and biocompatibility of incorporated polyethylenimine nanoparticles. Biomaterials 2008; 29 (31): 4157-63.

Gunyakti N, Gur G, Misirligil A. [In vivo adhesion of Streptococcus mutans on amalgam and composite restorative materials]. Ankara Univ Hekim Fak Derg 1990; 17 (1): 83-6.

Chin MY, Busscher HJ, Evans R, et al.Early biofilm formation and the effects of antimicrobial agents on orthodontic bonding materials in a parallel plate flow chamber. Eur J Orthod 2006; 28 (1): 1-7.

Sukontapatipark W, el-Agroudi MA, Selliseth NJ, et al. Bacterial colonization associated with fixed orthodontic appliances. A scanning electron microscopy study. Eur J Orthod 2001; 23 (5): 475-84.

Tufekci E, Dixon JS, Gunsolley JC, et al. Prevalence of white spot lesions during orthodontic treatment with fixed appliances. Angle Orthod 2011; 81 (2):206-10.

Roberson TM. Sturvedant's art and science of operative dentistry. 1. 5th ed 2006. chap 2: 65-77.

Imazato S, Ebi N, Takahashi Y, et al.Antibacterial activity of bactericide- immobilized filler for resin-based restoratives. Biomaterials 2003; 24 (20): 3605-9.

Yamamoto K, Ohashi S, Aono M, et al.Antibacterial activity of silver ions implanted in SiO2 filler on oral streptococci. Dent Mater 1996; 12 (4): 227-9.

Syafiuddin T, Hisamitsu H, Toko T, et al. In vitro inhibition of caries around a resin composite restoration containing antibacterial filler. Biomaterials 1997;18 (15): 1051-7.

Sodagar A, Bahador A, Khalil S, et al.The effect of TiO2 and SiO2 nanoparticles on flexural strength of poly (methyl methacrylate) acrylic resins. J prosth res 2013; 57 (1): 15-9.

Leung D, Spratt DA, Pratten J, et al.Chlorhexidine-releasing methacrylate dental composite materials. Biomaterials 2005; 26 (34): 7145-53.

Jedrychowski JR, Caputo AA, Kerper S. Antibacterial and mechanical properties of restorative materials combined with chlorhexidines. J Oral Rehabil 1983; 10 (5): 373-81.

Sawai J. Quantitative evaluation of antibacterial activities of metallic oxide powders (ZnO, MgO and CaO) by conductimetric assay. J MicrobMeth 2003; 54 (2): 177-82.

Jones N, Ray B, Ranjit KT, et al.Antibacterial activity of ZnO nanoparticle suspensions on a broad spectrum of microorganisms. FEMS Microbiol Lett 2008; 279 (1): 71-6.

Hernandez-Sierra JF, Ruiz F, Pena DC, et al. The antimicrobial sensitivity of Streptococcus mutans to nanoparticles of silver, zinc oxide, and gold. Nanomedicine 2008; 4 (3): 237-40.

Spencer CG, Campbell PM, Buschang PH, et al. Antimicrobial effects of zinc oxide in an orthodontic bonding agent. Angle Orthod 2009; 79 (2): 317-22.

Aydin Sevinc B, Hanley L.Antibacterial activity of dental composites containing zinc oxide nanoparticles. J biomed mater res Part B, Applied biomater 2010; 94 (1): 22-31.

Pinto RJ, Fernandes SC, Freire CS, et al. Antibacterial activity of optically transparent nanocomposite films based on chitosan or its derivatives and silver nanoparticles. Carbohydr Res 2011;348: 77-83.

Uysal T, Akkurt MD, Amasyali M, et al. Does a chitosan-containing dentifrice prevent demineralization around orthodontic brackets?. Angle Orthod 2011; 81 (2): 319-25.

Friedman M, Juneja VK. Review of antimicrobial and antioxidative activities of chitosans in food. J Food Prot 2010; 73 (9): 1737-61.

Yang YJ, Chuang CC, Yang HB, et al.Lactobacillus acidophilus ameliorates H. pylori-induced gastric inflammation by inactivating the Smad7 and NFkappaB pathways. BMC microbiology 2012; 12: 38.

Alt V, Bechert T, Steinrucke P, et al.An in vitro assessment of the antibacterial properties and cytotoxicity of nanoparticulate silver bone cement. Biomaterials 2004; 25 (18):4383-91.

Ahn S, Vang MS, Yang HS, et al.Histologic evaluation and removal torque analysis of nano- and microtreated titanium implants in the dogs. J adv prosthod 2009; 1 (2): 75-84.

Poosti M, Ramazanzadeh B, Zebarjad M, et al. Shear bond strength and antibacterial effects of orthodontic composite containing TiO2 nanoparticles. Eur J Orthod 2012; 35 (5): 676-9.

Tavassoli Hojati S, Alaghemand H, Hamze F, et al. Antibacterial, physical and mechanical properties of flowable resin composites containing zinc oxide nanoparticles. Dent Mater 2013; 29 (5): 495-505.

Fernandes JC, Tavaria FK, Soares JC, et al. Antimicrobial effects of chitosans and chitooligosaccharides, upon Staphylococcus aureus and Escherichia coli, in food model systems. Food Microbiol. 2008; 25 (7): 922-8.


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