Adhesion

Does rheology have an effect on adhesion? The following recent article is an interesting introduction



2010

International Journal of Adhesion and Adhesives 30(2010) 393-402
Determining the initial viscosity of 4 dentinal adhesives. Relationship with their penetration into tubuli.
Leforestier E, Darque-CerettiE, Peiti Ch, Bouchard P-O, Bolla M

A Reologica Stresstech Rheometer with Couette geometry for low viscosity material measured viscosity of three three adhesive systems at gap 0.1mm, shear rate of 0-5000 reciprocal seconds and constant temperature of 25C. Parallel plate geometry for a higher viscosity material measured the viscosity of the “dual” adhesive which polymerises in the absence of oxygen. The temperature in this case was varied from 10-37C
Result: The variation in viscosity affects the time for material to penetrate tubuli but at manufacturer’s recommended time of 20 seconds the viscosity effect is not an important decisive factor in its adhesion.