Abstract:
Purpose was to determine the viscoelastic properties of three root canal sealers as a function
of temperature, time and frequency using dynamic oscillatory measurements. Methods: Measurements
were performed on the dynamic oscillatory rheometer set to temperatures: 25°C, 35°C, 40°C and 65°C.
Stress sweep and frequency sweep tests were used in order to determine storage moduli G’, loss moduli
G’’ and complex viscosity η*
. Results Higher values of storage compared to loss moduli indicate the
more pronounced solid-like behavior of tested materials. EndoREZ showed the highest values of G’ and
G’’ moduli at all temperatures. With temperature increase the G’ and G’’ moduli of Sealapex and
EndoREZ increased while the moduli of AH Plus decreased. With frequency increase all materials
showed viscosity decrease exhibiting non-Newtonion, shear-thinning behavior. With temperature
increase AH Plus demonstrated viscosity decrease, while the viscosity of Sealapex and EndoREZ
increased. Clinical significance: All tested materials were temperature, time and frequency dependent
and this dependency varied between them. The obtained results may be used to predict the rheological
behavior of root canal sealers in different temperature conditions, thus helping as to estimate optimal
handling characteristics for specific clinical applications.
