2 shrinkage stress – GC EUROPE Kalore User Manual

Page 15

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15

Volumetric Shrinkage (%)

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

Filtek Supreme DL

Filtek Z250

Filtek Silorane

Prisma TPH3

EsthetX

Premise

Estelite Quick

4 Seasons

Grandio

Tetric Evoceram

Clearfil Majesty Esthetic

Venus

CeramX Mono

KALORE

Shrinkage stress in MPa

0

5

10

15

20

25

1

5 10 15 30 60 120 180 240 300 600 900 1200 1500 1800

Seconds

KALORE

Grandio

CeramX Mono

Tetric Evo Ceram

Venus

GC Kalore technical manual

Setting shrinkage was measured
in-house, in accordance with ISO Draft
2007-07-10 Dentistry - Polymerization
shrinkage of filling materials. Pre- and
post-curing composite resin densities
were measured and the polymerization
shrinkage calculated accordingly.
KALORE demonstrated one of the
lowest levels of volumetric shrinkage
of all composites tested (Fig. 11).

Figure 11. Volumetric shrinkage of various composite materials.

Source: GC Corporation.

6.2 Shrinkage Stress

Independent Testing - ACTA

independent testing of setting
shrinkage stress using a tensilometer
was conducted at the acta,
amsterdam. the composite material
was inserted in a cylindrical shape
between a glass plate and a parallel
flat surface metal bolt head that was
connected to a load-cell (the moving
part). using the tensilometer test,
contraction stress values vary with the
ratio of bonded to free surface area,
known as the configuration factor or
c-factor. a c-factor of 2 was used in
the experiments. The contraction
stress values represent the force
required to combat the axial shrinkage
of the composite and maintain the
initial distance between the parts. The materials were light-cured for 40 seconds with an Elipar
Highlight in standard mode (750 mW/cm2). Shrinkage stress was measured for 30 minutes, while
counteracting the axial contraction of the samples continuously by using a feedback
displacement of the crosshead to keep the thickness of the sample constant at 0.8 mm. This
simulated a restoration in a fully-rigid situation where the cavity walls cannot yield to contraction
forces. KALORE demonstrated the least shrinkage stress (Fig. 12).

Figure 12. Shrinkage stress of various composite materials versus time.

Source: ACTA, Amsterdam.

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