Dental polyelectrolyte cements: II: effect of powder/liquid ratio on their rheology.

The rheological behaviour during the setting of a range of zinc polycarboxylate and glass ionomer dental cements has been studied. The influence of the powder/liquid ratio was found to alter the rate of reaction without altering the basic form of the kinetics. Two models were advanced to explain the rheological and chemical differences between the two types of polyelectrolyte cement. The setting of the glass ionomer cements was consistent with the development of a homogeneous polymer network whereas the zinc polycarboxylate cements were viewed as setting by an inhomogeneous core-growth reaction.