Biomedical Engineering Reference
In-Depth Information
Table 11.1
(Continued)
Nanoparticle/
Nanoscale Imaging
Technique Used
Parameters
Evaluated
Material Studied
Results
Nanocomposite material
(Filtek Supreme Plus
Universal) and the
nanoionomer restorative
material (Ketac
Nanofilled composite
material (Filtek Supreme
Plus Universal) and GIC
modified with nanofillers,
and nanofiller
Shear bond strength
Conventional orthodontic
composite had higher
shear bond strength than
nanocomposite and
nanoionomer groups
N100
Light Curing Nano-
Ionomer) and a
conventional orthodontic
composite material
(Transbond XT)
[17]
clusters
t
“
”
(Ketac
N100 Light
Curing Nano-Ionomer)
t
ECA material and two
conventional adhesives
(composite and
resin-modified glass
ionomer)
[18]
ECA was modified by the
addition of silica
nanofillers and silver
nanoparticles
Effect of surface
characteristics, physical
properties, and
antibacterial activities of
ECA against cariogenic
Streptococci
ECA had rougher surfaces
than conventional
adhesives due to addition
of silver nanoparticles and
bacterial adhesion to ECA
was less than to
conventional adhesives.
No significant difference in
shear bond strength and
bond failure interface
between ECA and
conventional adhesives
were noted
BisGMA/HEMA adhesive
modified with nanogel
[19]
Nanogel copolymers at a
70:30 molar ratio of
IBMA and either UDMA
or BisEMA
Adhesive viscosity, wet
mechanical properties,
short-term microtensile
bond strength
Parameters evaluated were
enhanced by nanogel
inclusion in the adhesive
resin
enhance the long-term optical properties by virtue of their small size, and at the same time provide
superior mechanical strength and wear resistance. Ever since the first formulation of composite
resins in the 1960s, the basic compositional triad has been used: monomer, silane-treated filler,
and initiators.
Filler particles improve the mechanical properties of the composite material. The filler used by
Bowen in 1963
[24]
, consisted of milled quartz particles with average size ranging from 8 to 12
m
µ
(8000
12,000 nm). Due to the esthetic limitations of macrofilled composites (lack of surface
gloss), the minifilled composite was introduced in the 1970s. Improvement in properties such as
tensile and compressive strength (CS), modulus of elasticity, abrasion resistance, radiopacity,
esthetics, and handling was noted with higher filler load. The filler material used was silica parti-
cles of average diameter of 400 nm allowing a maximum filler loading of 55 wt%, with better
polishability, but with a significantly lower mechanical strength
[25]
. It was not until the 1980s and
1990s that mixtures of filler materials were tested. These hybrid fillers (600
2000 nm) were
