GC EUROPE Kalore - Manual (Page 14)

14 GC Kalore technical manual
Independent Testing - Indiana University
independent testing of volumetric shrinkage on the same types of composites was conducted at
a third site by Dr. Jeffrey A. Platt in the Division of Dental Materials, Indiana University School of
Dentistry. Approximately 20 quarts of distilled water were poured into a Styrofoam container and
allowed to stand overnight. The next day, the water temperature was recorded and checked
periodically during the day for temperature stability. a density bottle was filled with water from
the container and a stopper inserted (taking care to avoid the incorporation of any air bubbles
into the vessel). the filled bottle was wiped dry and its weight recorded to the nearest 0.0001
gram. this procedure was repeated four times to obtain the average weight (used in the
calculations for the value “B”). To obtain value “C”, the bottle was filled approximately one-half
full with distilled water, and approximately one gram of unpolymerized material was added. The
bottle was then completely filled, weighed as above, and the average of three weight
measurements used to determine the value for “c”. the unpolymerized sample weights were
recorded as a mean of three weights and used as value “D” (n=3).
unpolymerized material was placed between two pieces of polyester film and squeezed to a
thickness of about 1.5-2.0 mm. These samples were cured from both sides for 30 seconds each (for
a total cure time of one minute). the cured samples were introduced to the density bottle in the
same manner as previously described for the unpolymerized samples. mean weights were used in
the calculations for value “e”. the samples were weighed before placing in the bottles and the
mean of three measurements used as value “F” (n=3). Specimens were stored in sealed vials and
measurements made immediately post-polymerization, after one day and after seven days. the
volumetric polymerization shrinkage was obtained using equations:
Unpolymerized sample: U=(B-C+D)/D g/cm3
Polymerized sample: P=(B-E+F)/F g/cm3
Polymerization shrinkage PS=(1-P/U) x 100
the data for each time period (initial, 1 day and 7 days) were each subjected to one-way anOVa
tests. It was found that KALORE demonstrated significantly less volumetric polymerization
shrinkage than all other composites tested at all time periods (Table 3).
Table 3. Volumetric Polymerization Shrinkage.
all superscript letters indicate statistically similar groups. p<0.001 for contraction stress and p<0.01 for all other groups.
VPS (%)
initial One Day Day Seven
KalORe 0.92 ± 0.21a 0.55 ± 0.29a 1.15 ± 0.23a
Filtek Supreme Plus† 2.82 ± 0.19c 2.05 ± 0.23c 2.52 ± 0.12b
esthetX hD† 2.71 ± 0.34c 2.45 ± 0.56c 2.20 ± 0.29b
Premise† 1.87 ± 0.30b 1.20 ± 0.26b 2.14 ± 0.27b
tPh3† 3.48 ± 0.24d 3.10 ± 0.29d 2.99 ± 0.36c