Antibacterial amorphous calcium phosphate nanocomposite with quaternary ammonium salt and silver nanoparticles

Published

February 2, 2012

Author(s)

Nancy Lin, Lei Cheng, Michael D. Weir, Hockin H. Xu, Joseph M. Antonucci, Alison M. Kraigsley, Sheng Lin-Gibson, Xuedong Zhou

Abstract

Objectives. Calcium and phosphate ion-releasing resin composites are promising for remineralization; however, so far there has been no report on imparting a potent antibacterial capability to these composites. The objectives of this study were to incorporate quaternary ammonium dimethacrylate (QADM) and silver nanoparticles (NanoAg) into amorphous calcium phosphate nanocomposite (NanoACP) for the first time to obtain a strong antibacterial activity. Methods. Bis(2-methacryloyloxy-ethyl) dimethyl-ammonium bromide, the QADM, was synthesized with 2-(N,N-dimethylamino)ethyl methacrylate and 2-bromoethyl methacrylate. NanoAg was synthesized by dissolving Ag 2-ethylhexanoate salt in 2-(tert-butylamino) ethyl methacrylate. Composite disks were inoculated with Streptococcus mutans (S. mutans) and the CFU counts, metabolic activity, and lactic acid production of the biofilms were measured. Results. The flexural strength and modulus of NanoACP+QADM, NanoACP+NanoAg, and NanoACP+QADM+NanoAg matched those of two commercial control composites with no antibacterial property. The NanoACP+QADM+NanoAg composite decreased the CFU counts of S. mutans biofilms adherent on the composite by an order of magnitude, compared to the commercial composites. The metabolic activity and lactic acid production of the biofilms were also greatly reduced on the new nanocomposites. Combining QADM and NanoAg rendered the nanocomposite more strongly-antibacterial than that using either QADM or NanoAg alone. Significance. QADM and NanoAg were incorporated into calcium phosphate composite for the first time. NanoACP+QADM+NanoAg was strongly-antibacterial and greatly reduced the CFU counts, metabolic activity, and acid production of S. mutans biofilms, while possessing mechanical properties similar to commercial composites. The nanocomposite is promising to have the double benefits of remineralization and antibacterial capabilities to inhibit dental caries.

Citation

Dental Materials

Volume

28

Issue

5

Pub Type

Journals

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DOI Link

Keywords

amorphous calcium phosphate, antibacterial, biofilm, dental composite, dimethacrylate, oral bacteria, polymer, quaternary ammonium compound, silver nanoparticles, Dentistry

Citation

Lin, N. , Cheng, L. , Weir, M. , Xu, H. , Antonucci, J. , Kraigsley, A. , Lin-Gibson, S. and Zhou, X. (2012), Antibacterial amorphous calcium phosphate nanocomposite with quaternary ammonium salt and silver nanoparticles, Dental Materials, [online], https://doi.org/10.1016/j.dental.2012.01.005 (Accessed October 8, 2025)