Biomedical Engineering Reference
In-Depth Information
DTS, and 18 MPa in BFS). This cement also showed higher bond strength to dentin after 7 and
30 days of storage in distilled water. Gu et al.
[28]
mixed nanosized (5
15 nm) spherical Yttria-
stabilized ZrO
2
(YSZ) powders and microsized Y
2
O
3
stabilized ZrO
2
powders (5
m) with glass
ionomer. The SEM images are given in
Figure 5.5
. The experimental materials were characterized to
analyzed microhardness, CS and DTS. It was found that the microhardness values were in compari-
son for both materials; however, the CS and DTS of microsized particles were higher than nanosized
particles. It was due to high packing density of GIC with finely distributed large particles that can
ensure high mechanical strength. However, due to the extremely small particle size and large surface
area of the nanosized YSZ
80
μ
GIC composites, there might be insufficient ionomer to hold the large
amount of nanosized YSZ powders effectively. The nanosized YSZ
GIC composites can be
(A)
(B)
(C)
FIGURE 5.5
SEM micrographs of polished cross-sectional view of YSZ
GIC: (A) nanosized YSZ
GIC at low magnification;
(B) nanosized YSZσGIC at high magnification; and (C) microsized YSZGIC
[28]
.
