GC EUROPE Kalore - Manual (Page 12)

12 GC Kalore technical manual
5.5 GC Corporation’s Technology for Reduction of Shrinkage (Stress)
The new monomer DX-511, licensed from DuPont under an exclusive partnership agreement, is
based on urethane dimethacrylate chemistry and designed to combine excellent handling and
physical properties with low shrinkage (stress). DX-511 is compatible with all current composite and
bonding systems.
DX-511 Monomer
The molecular structure of DX-511 includes a long rigid core and flexible reaction arms. The long
rigid core retains its shape and size thereby overcoming the reduced capacity of flexible arms not
to fold and lose volume, which prevents monomer deformation and reduces shrinkage. the
flexible arms increase reactivity, overcoming the reduced reactivity usually associated with long
monomer chains (Fig. 8). The molecular weight of DX-511 (Mw 895) is twice the molecular weight
of Bis-GMA or UDMA, reducing polymerization shrinkage since a smaller number of carbon
double bonds (c=c) are present.
Filler System
the hDR filler content of 30% wt. is optimized to reduce shrinkage, while still allowing easy
shaping and manipulation of the material.
6.0 laboratory testing
Laboratory testing was conducted externally as well as in-house at GC Corporation. To first test the
hypothesis that the addition of the DX-511 monomer would result in improved properties of the
composite, testing was conducted comparing two sets of composite samples that were identical
except that one of the two groups had the addition of DX-511 monomer (KALORE). Specifically,
comparisons were made for shrinkage stress, three-body wear resistance and combined polish
retention/surface roughness. For the results of this testing, which confirmed the superiority of
KALORE containing the DX-511 monomer over the composite without the DX-511 monomer,
please refer to the document in the addendum. Extensive laboratory tests were also conducted
comparing KalORe with other contemporary composites.
Figure 8. DX-511 Monomer