Formation and preliminary in vitro evaluation of a zinc polycarboxylate cement reinforced with neat and acid-treated wollastonite fibers.

Zinc polycarboxylate dental cement is known to form both molecular and mechanical bonds with native tooth materials. However, its relatively weak mechanical properties limit its applications. Wollastonite fibers, with different aspect ratios, were blended with ZnO, prior to its mixing with polyacrylic acid, at weight percentages up to 25%. Setting time, density, compressive strength, and Young's modulus of the formed composites were determined. Composition and morphology of the composites were determined by XRD, IR, and SEM before and after treatment in simulated body fluids. A slight delay in the setting time of the composites was observed. An overall improvement in the compressive strength and modulus of these composites was observed up to 5 wt % of wollastonites, followed by a decrease with increasing the proportion of wollastonite in the composites. Immersion of these composites in SBF solutions resulted in the formation of apatite deposits on the surfaces of the reinforcing fibers.