Synthesis and Characterization of a Urethane Dimethacrylate Monomer Containing a Quaternary Ammonium Salt for Use as a Component of Orthodontic Adhesive Primer

Introduction: Quaternary ammonium compounds (QACs) are among the most commonly used antibacterial agents. This study aimed to describe the synthesis of a dimethacrylate monomer functionalized with a QAC and the effect of its addition on the properties of an orthodontic primer. Materials and Methods: Urethane dimethacrylate monomer functionalized with a QAC (UDMAQAC) was synthesized and then characterized by nuclear magnetic resonance spectroscopy (NMR) and Fourier transform infrared spectroscopy (FTIR).  ۵, ۱۰, ۱۵ and ۲۰% wt of UDMAQAC was added to an orthodontic primer (control group). FTIR analysis was used to measure the degree of conversion (DC). The bond strength of dental brackets was measured by shear bond test (SBS) and adhesive remaining index (ARI) was evaluated by stereomicroscope. Agar diffusion test and MTT assay were used to evaluate the antibacterial property and cell viability, respectively. Statistical analysis included one-way ANOVA with Tukey’s post hoc test and Kruskal-Wallis nonparametric test (P˂۰.۰۵). Results: Although the obtained data did not show significant differences between the SBS and DC of different groups, but the highest values were obtained by adding ۱۰ wt% monomer. Adding more than ۱۰ wt% UDMAQAC resulted in significant increase in antibacterial property. The ۱۵ and ۲۰ wt% groups showed significantly lower cell viability. Conclusions: Adding urethane dimethacrylate monomer functionalized with a QAC increased the antibacterial property of orthodontic primer without adverse effects on the DC and SBS values. However, according to the obtained results especially cell viability data, ۱۰ wt% UDMA containing QAC seems to be the most proper percent for use in orthodontic primer.

کلیدواژه ها:

Quaternary Ammonium Compound ، Antibacterial ، Bond Strength