Biomedical Engineering Reference
In-Depth Information
Acc.V
20.0 kV 3.0
Spot Magn
Det
WD
2
ยต
m
25000 x
SE
9.8
FIGURE 4.1
Scanning electron microscopy (SEM) of nanoclusters.
observations, i.e., the acid etch surface observed by Buonocore and then applied to dental enamel,
or mixing materials in order to improve properties which were shown to be effective as seen in pub-
lished manuscripts of Wilson and Kent since 1968 up to 1972 that culminated in the development of
glass ionomer cement.
The following decades of 1980s and 1990s were comprised by testing and discussing which den-
tal material behaves similarly to dental hard tissues. While exhaustion of this subject was reached,
nanotechnology field has gained attention. Therefore, a new question was asked: How nanotechnol-
ogy can be used to create materials capable of simulating the physical and mechanical behavior of
enamel/dentin?
Biomimetics has been the answer to this question. Biomimetics has been described as the sci-
ence that applies nanotechnology to create materials and devices that imitate nature. According to
Saunders (2009)
[4]
, biomimetics is supporting numerous improvement on nanofillers used in restor-
ative materials in dentistry. Besides the size that allows a higher amount of inorganic phase into the
composite, the shape, i.e., nanoclusters (
Figure 4.1
), nanorods, nanotubes, and nanofibers, has a sig-
nificant and positive influence on resin bonded composites' mechanical property.
The nanosized fillers inserted into resin composites lead to better physical and mechanical char-
acteristics. An optical advantage of high aesthetic potential, due to nanofillers of size 20 nm smaller
than visible light wavelength that ranges from 400 to 800 nm, enhances the translucency and color
(refer to Section 4.9). Significant augmentation of microhardness, diametral tensile, compressive
and flexural strengths are recorded when nanofillers are incorporated. Further composition changes
as CaPO
4
nanostructures
[5]
, caries preventive CaF
2
nanoparticles, and recombinant amelogenins are
being added in order to synthesize biomimetic composites. Therefore, in the near future, nanofilled
