Antibacterial orthodontic adhesive incorporating polyethyleneimine nanoparticles

Nathan Zaltsman, Dana Kesler Shvero, David Polak, Ervin I. Weiss, Nurit Beyth*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Purpose: To evaluate the antibacterial, mechanical and biocompatibility characteristics of an orthodontic adhesive that contains quaternary ammonium polyethyleneimine (QPEI) nanoparticles. Materials and Methods: QPEI nanoparticles were added to an orthodontic adhesive at 0%, 1% and 1.5% wt/wt. Antibacterial activity was tested after aging for 14 days using the direct contact test (DCT). The degree of monomer conversion (DC) was measured using Fourier transform infrared (FTIR) spectroscopy. Shear bond atrength (SBS) was tested on the etched enamel of extracted human teeth. Biocompatibility was tested using keratinocyte and neutrophil cell lines in the XTT assay. Results: The DCT results showed significant bacterial growth inhibition in the test group incorporating 1.5% wt/wt QPEI nanoparticles (p < 0.05). The DC of the 0%, 1%, and 1.5% wt/wt samples measured immediately and after 10 min was 62.2-71.0%, 59.1-68.7%, and 52.9-58.6%, respectively, and the average SBS were 9.25 MPa, 11.57 MPa, and 9.10 MPa, respectively. Keratinocyte and neutrophil viability did not change following the addition of QPEI to the orthodontic adhesives. Conclusions: The incorporation of QPEI nanoparticles into orthodontic cement provides long-lasting antibacterial activity against Streptococcus mutans without reducing the strength of adhesion to enamel, the degree of double bond conversion during the polymerisation, or the biocompatibility of the orthodontic cement.

Original languageEnglish
Pages (from-to)245-250
Number of pages6
JournalOral health & preventive dentistry
Issue number3
StatePublished - 2017
Externally publishedYes


  • Antibacterial nanoparticles
  • Orthodontic adhesive
  • Shear bond strength


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