GC EUROPE G-aenial Bond - Manual (Page 12)

12 G-ænial Bond Technical Manual
7.0 Physical properties – Results of in Vitro Studies
7.1 the mechanisms of adhesion to enamel and dentine
the adhesion of G-ænial Bond relies on both micro-mechanical retention and chemical bonding
principles.
7.1.1 micro-mechanical interlocking
under aqueous conditions, the two functional monomers (4-met and phosphoric acid ester)
dissolve the smear layer and mildly etch enamel and dentine surfaces, thereby creating micro-
porosities on enamel and increasing the surface available for bonding. at the same time, it will
partially demineralise the outer dentine layer, leaving space between the collagen networks for
resin infiltration which leads to the formation of a hybrid layer. the depth of the demineralised zone
is the same as the depth of the resin infiltration, which means that the collagen network will remain
protected (rather than part of it becoming exposed), therefore there is no risk of hydrolytic
degradation or associated nano-leakage.
SEM observations - Tests conducted by GC R&D, Japan
Sem observations were conducted in order to characterise the demineralisation patterns after
application of G-ænial Bond to enamel and dentin.
Test set-up: G-ænial Bond was applied to the tooth surface, after the surface had been polished with #600 grit Sic paper. after
10 seconds, the adhesive was washed out with acetone, and the Sem images were taken.
Figure 7: Observation of demineralisation patterns on enamel (left) and dentine (right) under Sem microscopy, magnification
x2000. Source: Gc corporation, Japan, 2009
the demineralisation patterns generated by application of G-ænial Bond on enamel can be
observed in Figure 7 left. Due to its relatively low ph of 1.5, G-ænial Bond induced effective
demineralisation of enamel (also demonstrated by the small amount of remaining smear layer) and
the creation of micro-porosities.
the Sem of dentine (Figure 7 right) also demonstrates good demineralisation with the application
of G-ænial Bond. nevertheless, the dentinal tubules remain occluded, reducing the risk of post-
operative sensitivity.
Enamel Dentine