GC EUROPE G-aenial Bond - Manual (Page 13)

13 G-ænial Bond Technical Manual
7.1.2 chemical interaction
While micro-mechanical interlocking is hypothesized to be the basis for good adhesion, recent
publications have demonstrated that additional chemical interaction between the functional
monomers and the tooth substrate could improve the bond durability.
4 this is known as the
“adhesion-Decalcification” (or aD) concept.
the two functional monomers can form a complex with the remaining calcium salts of the
hydroxyapatite crystals, which is the basis for the chemical interaction. this results in the formation of
an extremely strong layer with low solubility, known as the nano-interaction zone (niZ). the amount
of residual apatite crystals is of great importance in ensuring the subsequent quality of adhesion.
TEM observations
Tests conducted by GC R&D, Japan
to assess the quality of the dentine/ adhesive interface of various bonding agents, transmission
electron microscope (tem) observations were conducted on non-demineralised and on
demineralised specimens.
Test set-up: two 0.8 mm-thick specimens of human dentine/ adhesive interface were prepared. One of the specimens was left
untreated, i.e., non-demineralised (Figure 8), while the other specimen was demineralised with eDta solution (Figure 9 and
Figure 10). each specimen was embedded in an epoxy resin and ultrathinned to 80-90 nm thickness. after carbon-spattered,
the interfacial zone was observed using tem.
table 5: application technique of adhesives tested
Product name manufacturer category etching
and rinsing
Bottle 1 air drying Bottle 2 air drying light-
curing
G-ænial Bond Gc 1-step
self-etch
/ 10 s application strong 5 s / / 10 s
Bond Force tokuyama 1-step
self-etch
/ 20s application weak 5 s and
moderate 5 s
/ / 10 s
clearfil Se Bond Kuraray 2-step
self-etch
/ 20 s mild apply gently 10 s
Optibond Fl Kerr 3-step etch-
and-rinse
15 s + 15 s 15 s 5 s 15 s 3 s 20 s
in the specimens that were not demineralised (Figure 8), no hybrid layer was observed for either
the G-ænial Bond or Bond Force tem samples. a hybrid layer of 1µ and one of 5µ was observed
with clearfil Se Bond and Optibond Fl respectively.
4 Van meerbeek B. et al., State of the art self-etch adhesives, Dent. mat. 2011;27:17-28.