Abstract
Enamel demineralization is a common problem found in patients using orthodontic devices, such as orthodontic braces. It was found that Streptoccocus mutans growth increases adjacent to orthodontic devices, which may result in caries development. Incorporated antibacterial quaternary ammonium polyethylenimine (QPEI) nanoparticles were previously shown to be highly efficacious against various bacteria. Combining antibacterial materials in orthodontic cement may be advantageous to prevent bacterial outgrowth adjacent to orthodontic brackets. The aim was to evaluate the efficiency of orthodontic cement containing QPEI nanoparticles in reducing S. mutans and Lactobacillus casei outgrowth adjacent to orthodontic brackets. Orthodontic brackets were bonded to the buccal surfaces of extracted lower incisors. The antibacterial effect on S. mutans and L. casei outgrowth of Neobond bracket adhesive orthodontic cement with and without QPEI nanoparticles was compared. The antibacterial effect was evaluated using crystal violet staining and bacterial count (CFU/mL). The teeth in the experimental group, with the QPEI nanoparticles cement, showed significantly lower optical density (OD) values and CFU counts of S. mutans and L. casei than the teeth in the control group (p < 0.05). Based on the results, it can be concluded that orthodontic cement containing QPEI nanoparticles significantly inhibits S. mutans and L. casei growth around orthodontic brackets.
Highlights
Enamel demineralization, or white spot lesions (WSL), is a common complication found in patients using orthodontic devices, such as orthodontic braces
The biomass of S. mutans bacteria grown on the teeth in the presence of quaternary ammonium polyethylenimine (QPEI)
Nanoparticles was about 34% compared to the control group, and for S. mutans and L. casei biofilm the biomass was about 60% compared to the non-treated compared group (Table 2)
Summary
White spot lesions (WSL), is a common complication found in patients using orthodontic devices, such as orthodontic braces. The white chalky appearance of the enamel is due to demineralization of the enamel underneath the surface and an increase of enamel porosity, which changes the optical characteristics of the enamel. A meta-analysis by Sundararaj at el [1], reported that the incidence of new carious lesions formed during orthodontic treatment in patients was 45.8% and the prevalence of lesions in patients undergoing orthodontic treatment was 68.4%. Factors that may increase the incidence of white spot lesions are younger age at the start of treatment, poor oral hygiene, male patients, and duration of treatment. Res. Public Health 2018, 15, 606; doi:10.3390/ijerph15040606 www.mdpi.com/journal/ijerph
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