Novel dental adhesive containing antibacterial agents and calcium phosphate nanoparticles

Abstract

Secondary caries remains the main reason for dental restoration failure. Replacement of failed restorations accounts for 50-70% of all restorations performed. Antibacterial adhesives could inhibit biofilm acids at tooth-restoration margins, and calcium phosphate (CaP) ions could remineralize tooth lesions. The objectives of this study were to: (1) incorporate nanoparticles of silver (NAg), quaternary ammonium dimethacrylate (QADM), and nanoparticles of amorphous calcium phosphate (NACP) into bonding agent; and (2) investigate their effects on dentin bonding and microcosm biofilms. An experimental primer was made with pyromellitic glycerol dimethacrylate (PMGDM) and 2-hydroxyethyl methacrylate (HEMA). An adhesive was made with bisphenol-A-glycerolate dimethacrylate (BisGMA) and triethylene glycol dimethacrylate (TEGDMA). NAg was incorporated into primer at 0.1wt%. The adhesive contained 0.1% NAg and 10% QADM, and 0-40% NACP. Incorporating NAg into primer and NAg-QADM-NACP into adhesive did not adversely affect dentin bond strength (p>0.1). SEM showed numerous resin tags, and TEM revealed NAg and NACP in dentinal tubules. Viability of human saliva microcosm biofilms on primer/adhesive/composite disks was substantially reduced via NAg and QADM. Metabolic activity, lactic acid, and colony-forming units of biofilms were much lower on the new bonding agents than control (p<0.05). In conclusion, novel dental bonding agents containing NAg, QADM and NACP were developed with the potential to kill residual bacteria in the tooth cavity and inhibit the invading bacteria along tooth-restoration margins, with NACP to remineralize tooth lesions. The novel method of combining antibacterial agents (NAg and QADM) with remineralizing agent (NACP) may have wide applicability to other adhesives for caries inhibition.

Antimicrobial properties of conventional restorative filling materials and advances in antimicrobial properties of composite resins and glass ionomer cements—A literature review

“…Calcium phosphate nanoparticles were further added to the QADM and Nag to induce regenerative properties [3,8,106,[132][133][134][135][136][137]. Addition of calcium-fluoride and chlorhexidine to further enhance remineralization and antibiofim properties was also successful [138].…”

“…Dental composites and adhesives with quaternary ammonium dimethacrylate (QADM) and nanoparticles of silver (Nag) have been produced and were found to inhibit S. mutans [3,[129][130][131]. Calcium phosphate nanoparticles were further added to the QADM and Nag to induce regenerative properties [3,8,106,[132][133][134][135][136][137].…”

“…Several types on nanoparticles have been used to impart antimicrobial properties to dental materials [2,3,9,12,[118][119][120][121]. Nanoparticles' good antibacterial properties have been attributed to their large surface area to volume ratios [9].…”

Investigation of Bacterial Adhesion on Nanoparticle Filler-Reinforced Dental Composites after Different One-Step Finishing Timing Using a Constant-Depth Film Fermenter

“…Live bacteria were stained with Syto 9 to produce a green fluorescence, and bacteria with compromised membranes were stained with propidium iodide to produce a red fluorescence. The stained discs were examined using an epifluorescence microscope (TE2000-S, Nikon, Melville, NY) [20].…”

Nanomaterials in dentistry – potential capabilities, applications, limitations and hazards. Review of the literature. Part 2

“…Antibacterial and NACP-containing bonding agents may help inhibit residual bacteria in the tooth cavity, hinder invading bacteria along the margins, and remineralize lesions. The unique method for simultaneously incorporating NACP, a remineralizing agent, and NAg, an antibacterial agent, in the same adhesive may have extensive applicability in other bonding systems, cements, and novel dental adhesives [25].…”