Traditional one-layer adhesives were permeable, which may have caused sensitivity, faster degradation, and incompatibility with slow-curing resin materials. The two-layer adhesive system, utilizing a hydrophobic second layer to eliminate these issues, is considered the “gold standard”. Current single-layer universal adhesives are designed to be as hydrophobic as a 2-layer systems. Only these hydrophobic 1-layer systems are as good as the 2-layer gold standard.
Published on Aug 11th 2015