Dental polyelectrolyte cements. III. Effect of additives on their rheology

As part of a series of investigations of dental polyelectrolyte cements, the influence of additives was studied by viscometry. At low concentrations, tartaric acid was found to exert an accelerating influence on glass ionomer cements but to retard the reaction by complex formation at high concentrations. When dissolved with the liquid component, NaF accelerated some glass ionomer cements and retarded others. NaCl was found to accelerate the zinc polycarboxylate cements, possibly through its reduction in the electrical potential between powder and liquid phases. Neutralization of the polyacids retarded the reactions but not enough to indicate that hydrogen ions were directly involved in the rate determining step.