Antimicrobial Properties and Shear Bond Strength of Composite Used in Orthodontics Following the Addition of Curcumin-Reduced Nanographene Oxide

Background: Composites used in the direct bonding of brackets in fixed orthodontics are considered a suitableenvironment for the multiplication of cariogenic bacteria and the establishment of microbial plaques by creatinga distance between the bracket, tooth surface, and surface properties such as porosity. In the present study,we decided to combine curcumin-reduced nano-graphene oxide (rGO-NCUR) with a composite resin usedin orthodontics to achieve a composite with optimal shear bond strength (SBS) and antimicrobial propertiesagainst Streptococcus mutans as a main cariogenic bacterium.Methods: In the present study, nanoparticle of graphene oxide (NGO) was synthesized by the modifiedHummers’ method using graphite powder and reacted by NCUR to regenerate reduced-NGO (rGO-NCUR).Scanning electron microscopy (SEM) was used to confirm the synthesis of NGO, NCUR, and rGO-NCUR. SBSand antimicrobial activity of Transbond XT composite containing ۵% rGO-NCUR were performed against S.mutans biofilms. SPSS software, one-way ANOVA test, and Tukey post hoc test with a significance level equalto or less than ۰.۰۵ were used to analyze the data.Results: The synthesis of NGO, NCUR, and rGO-NCUR in nanoscale was confirmed by SEM. The amountof SBS in the composite sample with ۵% w/w rGO-NCUR was ۱۲.۳۰ ± ۰.۶۵ MPa. The optical density of S.mutans in the biofilm structure formed on composite containing ۵% w/w rGO-NCUR was significantly reduced(۶۲.۱۰%) compared with the control group, namely, original composites used in orthodontics (P < ۰.۰۵).Conclusions: Based on the data of the present study, it can be concluded that composite containing ۵% w/wrGO-CUR, without adverse effect on the physical-mechanical properties of composites, can be used as anantimicrobial additive of composites used in orthodontics to control biofilm formation and caries aroundorthodontic brackets.

کلیدواژه ها:

Nanoparticles ، Curcumin ، Graphene oxide ، SBS ، Streptococcus mutans