Biomedical Engineering Reference
In-Depth Information
by several scientific groups as the father of nanotechnology. It is important to point out that many
current researchers are focused on bringing into reality the Feynman's “futuristic” ideas
[1
3]
.
Nano comes from the Greek term nanos, which means “dwarf,” and refers to things whose
dimensions are a billion-fold smaller than the precedent unit, e.g., 1 nm represents a thousandth of
a thousandth of a thousandth (0.000,000,001 or 10
2
9
) part of 1 m. It is important to point out that
nature has designed several biological systems, including structures of the oral cavity, within the
nanometer range.
Figure 23.1
shows the different scales (macro-, micro- and nanoscale) and
the dimensional sizes of some representative dental materials
[4,5]
. A nanometer is so small that it
is very difficult to conceptualize it. Light microscopy cannot observe a nanosystem in its real size
and the use of high-resolution microscopies is necessary (e.g., scanning or transmission electron
microscopy, atomic force microscopy, scanning probe microscopy, etc.).
A material at the nanoscale is expected to have different properties and behavior than larger par-
ticles due to the fact that nanosystems have a much greater surface area. Less material can be used
for specific important technological, economic, and environmental applications. The large surface
area causes nanosystems to be more reactive than larger particles and some of the fundamental
0.1 nm
1 nm
10 nm
100 nm
1
µ
m
10
µ
m
100
µ
m
1 mm
1 cm
Meters
10
−
10
10
−
9
10
−
8
10
−
7
10
−
6
10
−
5
10
−
4
10
−
3
10
−
2
10
−
1
10
2
10
3
10
4
10
5
10
6
10
7
Nanometers
10
1
Cells
Molecules
Organelles
Atoms
Atomic force microscopy
(AFM)
Minimum resolution with
optical microscope
Minimum resolution with
scanning electron microscope
Minimum resolution of the
human eyes
FIGURE 23.1
Representation of macro-, micro-, and nanoscales and the dimensional sizes of some representative dental
systems.
