Quantum Dots of Tantalum Oxide with an Imidazolium Ionic Liquid as Antibacterial Agent for Adhesive Resin.

Purpose: To synthesize tantalum oxide quantum dots (Ta(2)O(5)QDs) using an imidazolium ionic liquid as a precursor and evaluate the effect of its addition to an experimental adhesive resin on the degree of conversion (DC) and antibacterial activity. Materials and Methods: Ta(2)O(5)QDs was synthesized from the hydrolysis of an imidazolium ionic liquid (1-n-decyl-3-methylimidazolium hexachlorotantalate [DMI center dot TaCl6]) and evaluated by transmission electron microscopy (TEM). The adhesive was formulated with 66.7 wt% bisphenol A-glycidyl methacrylate (bis-GMA), 33.3 wt% 2-hydroxyethyl methacrylate (HEMA) with a photoinitiator/co-initiator system. In one group, Ta(2)O(5)QDS was added to the adhesive at 1 wt% Ta(2)O(5)QDs) and one group remained without Ta(2)O(5)QDS as control (CTRL). The adhesives were evaluated for DC by Fourier Transform Infrared spectroscopy. Direct contact inhibition assay was used to evaluate the antibacterial activity of the experimental adhesive resins against biofilm formation and planktonic bacteria. Results: Ta(2)O(5)QDs had a particle size distribution of 1.52 +/- 0.73 nm. DC was 50.91 +/- 4.94% for CTRL and 55.4 +/- 4.58% for Ta(2)O(5)QDs (p = 0.310). Ta(2)O(5)QDs showed less Streptococcus mutans biofilm formation on adhesive surfaces (p = 0.013). There was no statistically significant difference in terms of antibacterial activity against planktonic bacteria (p = 0.079). Conclusion: Non-agglomerated Ta(2)O(5)QDs synthesized from an imidazolium ionic liquid provided antibacterial activity to the experimental adhesive resin against biofilm formation of Streptococcus mutans.