Biomedical Engineering Reference
In-Depth Information
adverse effects. The chemistry and composition of the nanomaterials are extremely different—
some might degrade fast, others have a long biological half lifetime, or they are completely inert
with potential effects on cellular and subcellular structures. It is to be expected that biological or
biomimetic nanomaterials mean a minor hazard than completely artificial preparations such as
carbon nanotubes or silver nanoparticles.
Nanosized structures are present in milk and other foods. Due to abrasion and attrition, nano-
sized HA particles are assumed to be present in the oral fluids
[16]
. Due to these considerations,
future research should focus on biological and biomimetic approaches. The fauna and the flora
offer many unexplored strategies which could be helpful for dental prophylaxis and biofilm man-
agement. The famous lotus effect, though not directly applicable for the adoption in the oral cavity,
is only one prominent example. Experts in dental research have to define the demands not only
from a clinical point of view but also especially with respect to the surface interactions in the oral
cavity; cooperating scientists are to explore possible solutions in the nature. Only interdisciplinary
research will lead to really new strategies in preventive dentistry based on nanotechnology.
Thereby, the patients and the society become more and more interested in biological approaches.
Despite all these promising strategies and research approaches, the application of nanosized par-
ticles or materials in the oral cavity requires a thorough examination of potential risks. Especially,
artificial nanosized particles such as nanotubes mean unpredictable hazards for the human
organism; because their degradation is not provided. Thus, biologic or biomimetic strategies seem
to be advantageous. However, also the fate and behavior of these substances in the organism
require further research since the processing and modification of the basically biological materials
possibly alter the process of degradation. This also applies for slight differences of native and bio-
mimetic HA nanoparticles. To the best knowledge of the authors, there are no publications so far
on this relevant topic investigating the special characteristics of already available preparations
[9,14,16]
. Nanomaterials applied as components of mouth rinses or dentifrices could mean an
unphysiological challenge for the organism, and several models are discussed for the oral uptake of
nanoparticles
[113
115]
. Besides the size of the particles, their physicochemical properties deter-
mine their interaction with the physiological barriers and the cells. Organic nanoparticles not only
might be digested or hydrolyzed by proteolytic enzymes or denatured by gastric juice but could
also be resistant to these mechanisms. Both organic and inorganic nanoparticles can interact with
organic molecules in saliva, mucous layer, or blood respectively. This nanoscaled process of bioad-
hesion of course modifies the possible resorption and properties of the protein-covered particles
with possible impact on the function of underlying cells and structures. The interaction of nanoma-
terials with acellular layers of the orogastrointestinal tract has been investigated
[115]
. Often, but
not always, smaller particles pass mucous layers much faster than bigger ones. This is modulated
by the surface charge of the particles
[115,116]
.
8.11
Conclusions
Some biomimetic nanomaterials seem to be promising amendments for dental prophylaxis, but
fundamental research is necessary in this field, before any clinical recommendations are possible.
