GC EUROPE Kalore - Manual (Page 13)

13
Shrinkage (%)
0
0.5
1
1.5
2
2.5
3
Esthet-X HD † TPH3 † KALORE Premise † Filtek Supreme †
d
c
b
a
a
KALORE Grandio † CeramX Mono † Tetric Evo Ceram † Venus †
Shrinkage (Vol.%)
0
2
4
6
8
10
12
14
1 5 10 15 30
Minutes
GC Kalore technical manual
6.1 Shrinkage
Independent Testing - ACTA
independent testing of volumetric
setting shrinkage was conducted for
several composites at the acta,
amsterdam. measurements were
continuously recorded using a mercury
dilatometer. to conduct the test,
composite was applied to the bottom
surface of a glass stopper, which was
then inserted into the mercury
dilatometer. the sample was light-cured
through the glass for 40 seconds with
an Elipar Highlight (750 mW/cm2). a
computer was used to follow the
shrinkage for a period of 4 hours or
more at 23°c. to calculate the
volumetric shrinkage, density
measurements were performed after
each shrinkage measurement using a
mettler toledo at 261 Delta Range (mettler instruments aG). Volumetric shrinkage was lowest
for KALORE (Fig. 9).
Figure 9. Volumetric shrinkage of various composite materials versus time.
Source: ACTA, Amsterdam.
Independent Testing - OHSU
Independent testing of volumetric shrinkage was also conducted by Dr. Jack Ferracane, in the
Division of Biomaterials at OHSU School of Dentistry in Portland, OR. Volumetric shrinkage (VS)
for three composites was determined in a mercury dilatometer. Composite samples weighing 150
mg were placed on glass slides that had been sandblasted with aluminum oxide (150 µm
particles) and coated with a silane coupling agent. the glass slide was clamped to the
dilatometer column, on top of which a linear variable differential transducer (lVDt) was placed in
contact with the surface of the mercury. the composite was photoactivated through the glass
slide for 60 seconds at approximately 350-400 mW/cm2. LVDT readings were recorded for 60
minutes at room temperature and correlated to volumetric shrinkage, based on data on
composite mass and density that had been determined by the archimedes method. the thermal
expansion produced by the heat generated from the curing light was subtracted from the results
by photoactivating for another 30
seconds after 60 minutes of data
acquisition, and following the
volumetric change for 30 minutes. the
specimens were considered “fully”
cured, i.e., cured with sufficient energy
to maximize polymerization. Statistical
testing of the data (ANOVA/Tukey’s
test) was performed to compare the
three composites (p < 0.05).
Significantly less polymerization
shrinkage was found with KALORE
and Premise† compared to other
composites (Fig. 10).
Figure 10. Volumetric Shrinkage.
a. not statistically different.