Purpose
Resin composites withholding antibacterial properties may be useful in preventing recurrent
caries. Covalently attached antibacterial polymers are a possible solution.This in vivo study
would evaluated the antibacterial effect of alkylated polyethylenimine nanoparticles
incorporated into flowable and hybrid composite resin disks embedded in a palatal
removable appliance.The disks would be in close contact with the palate in order to check
for contact mucosities. disks on the side facing the Tongue would be evaluated for their
antibacterial potency with confocal laser scanning microscopy.
Study start: March 2006
Composite resin materials are widely used in the dental clinic for replacement of hard
tissues. Although the mechanical properties and wear resistance of these materials have
been improved substantially, their antibacterial properties are still limited. These resin-based
materials accumulate more dental plaque than other restorative materials both in vitro, and in
vivo, which may result in secondary caries. A number of reports described experiments in
which composite resins were impregnated with antibacterial agents such as antibiotics,
silver ions, iodine and quaternary ammonium compounds, and gradually released them.
However, release of antibacterial agents into the surrounding milieu at various releasing
rates had several disadvantages: a decrease in the mechanical properties of the carrier
material over time, short-term effectiveness, and possible toxicity if the release is not
properly controlled. As compared with conventional antibacterial agents of low molecular
weight, the advantage of polymeric antibacterial agents is that they are nonvolatile,
chemically stable, can be chemically bound within the polymer carrier via active groups for
improved integration in the composite, and are difficult to penetrate through the skin. It has
been reported that polycations exhibit antibacterial properties, i.e. interact with and disrupt
bacterial cell membranes. A number of polymers with antibacterial properties were
developed for this purpose, including soluble and insoluble pyridinium-type polymers
involved in surface coating. Several reports have described incorporation of a
methacryloyloxydodecylpydidinium bromide (MDPB) monomer in composite resins that
showed no release of the incorporated monomer but still exhibited antibacterial properties.
The objective of this study is to evaluate clinically the safety and efficacy of alkylated
polyethylenimine (PEI) nanoparticles in composite resin restorative materials . In an in vitro
study, addition of a small percent (1% w/w) of nanoparticles did not affect significantly the
flexural strength of the commercial materials. The mechanical properties of the new
composites were close to those of the original composite, but exerted a strong antibacterial
activity upon contact that lasted for at least six months.
methods:alkylated polyethylenimine (PEI) nanoparticles added (1% w/w)to hybrid
composite resin disks embedded in a palatal removable appliance.The disks would be in
close contact with the palate in order to check for contact mucosities. disks on the side
facing the Tongue would be evaluated for their antibacterial potency with confocal laser
scanning microscopy.
Study chairs or principal investigators
Ervin I Weiss, DMD, Study Chair, Hadassah Medical Organization
Avi Domb, Phd, Study Director, Hebrew University Of Jerusalem
Michael M Perez Davidi, DMD, Principal Investigator, Hadssah Medical Orgenization
For Deatiles: www.clinicaltrials.gov/
© 2005-2006 NanoPharmaceuticals.org. All rights reserved. No part of this Internet site may be
reproduced without prior written permission of the copyright holder. Terms & Disclaimer
