Evaluation of the antibacterial activity of a conventional orthodontic composite containing silver/hydroxyapatite nanoparticles.
BACKGROUND
One of the most important complications of fixed orthodontic treatment is the formation of white spots which are initial carious lesions. Addition of antimicrobial agents into orthodontic adhesives might be a wise solution for prevention of white spot formation. The aim of this study was to evaluate the antibacterial properties of a conventional orthodontic adhesive containing three different concentrations of silver/hydroxyapatite nanoparticles.


METHODS
One hundred and sixty-two Transbond XT composite discs containing 0, 1, 5, and 10 % silver/hydroxyapatite nanoparticles were prepared and sterilized. Antibacterial properties of these composite groups against Streptococcus mutans, Lactobacillus acidophilus, and Streptococcus sanguinis were investigated using three different antimicrobial tests. Disk agar diffusion test was performed to assess the diffusion of antibacterial agent on brain heart infusion agar plate by measuring bacterial growth inhibition zones. Biofilm inhibition test showed the antibacterial capacity of composite discs against resistant bacterial biofilms. Antimicrobial activity of eluted components from composite discs was investigated by comparing the viable counts of bacteria after 3, 15, and 30 days.


RESULTS
Composite discs containing 5 and 10 % silver/hydroxyapatite nanoparticles were capable of producing growth inhibition zones for all bacterial types. Results of biofilm inhibition test showed that all of the study groups reduced viable bacterial count in comparison to the control group. Antimicrobial activity of eluted components from composite discs was immensely diverse based on the bacterial type and the concentration of nanoparticles.


CONCLUSIONS
Transbond XT composite discs containing 5 and 10 % silver/hydroxyapatite nanoparticles produce bacterial growth inhibition zones and show antibacterial properties against biofilms.
Department of Orthodontics, Faculty of Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
Ahmad
A
Sodagar
Radiation Applications Research School, Nuclear Science and Technology Research Institute, Tehran, Iran.
Azam
A
Akhavan
Tehran University of Medical Sciences, Tehran, Iran.
Ehsan
E
Hashemi
Department of Orthodontics, Faculty of Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
Sepideh
S
Arab
Department of Microbiology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
Maryam
M
Pourhajibagher
Tehran University of Medical Sciences, Tehran, Iran.
Kosar
K
Sodagar
Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
Mohammad Javad
MJ
Kharrazifard
Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran. abahador@tums.ac.ir.|Laser Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran. abahador@tums.ac.ir.|Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Keshavarz Blvd., 100 Poursina Ave., Tehran, 14167-53955, Iran. abahador@tums.ac.ir.
Abbas
http://orcid.org/0000-0001-5308-7208
A
Bahador
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D058491:Bacterial Load; D018441:Biofilms / Q000187:drug effects; D003188:Composite Resins / Q000737:chemistry / Q000494:pharmacology*; D003731:Dental Caries / Q000517:prevention & control; D003738:Dental Cements / Q000737:chemistry / Q000494:pharmacology*; D052978:Disk Diffusion Antimicrobial Tests / Q000379:methods; D004338:Drug Combinations; D017886:Durapatite / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D055032:Electron Microscope Tomography; D005899:Glass Ionomer Cements / Q000737:chemistry; D007779:Lactobacillus acidophilus / Q000187:drug effects / Q000254:growth & development; D008422:Materials Testing; D053758:Nanoparticles / Q000008:administration & dosage / Q000737:chemistry*; D016910:Orthodontic Brackets / Q000382:microbiology; D019279:Resin Cements / Q000737:chemistry / Q000494:pharmacology; D018030:Silver Compounds / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D013295:Streptococcus mutans / Q000187:drug effects / Q000254:growth & development; D013298:Streptococcus sanguis / Q000187:drug effects / Q000254:growth & development; D013997:Time Factors; D017001:Tooth Demineralization / Q000517:prevention & control
D000900:Anti-Bacterial Agents; D003188:Composite Resins; D003738:Dental Cements; D004338:Drug Combinations; D005899:Glass Ionomer Cements; D019279:Resin Cements; D018030:Silver Compounds; C477790:Transbond XT; D017886:Durapatite
Antimicrobial activity; Hydroxyapatite; Nanoparticles; Orthodontic; Silver