Abstract
Background: Zinc oxide (ZnO) that is a main component of Zinc Polycarboxylate and Zinc Phosphate conventional cements has
been incorporated into many dental materials for mechanical enhancement. Moreover, by decreasing the particle size of ZnO down
to nano-scale, its beneficial effects would tremendously increase because the nanoparticles have considerably higher surface to
volume ratio compared to micro-particles.
Objectives: The aim of this study was to assess mechanical, physical, and chemical properties of Zinc Polycarboxylate and Zinc
Phosphate cements containing Zinc oxide nanoparticles.
Methods: Three powder formulations were prepared for either of the cements based on the nanoparticles content (0 wt%, 10 wt%
before, and 10 wt% after sintering the powder). The prepared groups were compared with each other in terms of their compressive
strength, setting time, film thickness, and acid erosion resistance using one way ANOVA and Tukey HSD statistical tests (α = 0.05).
Results: Incorporating zinc oxide nanoparticles did not significantly change neither the film thickness nor the acid erosion resistance
of the cements (P > 0.05). Nevertheless, the setting time of zinc phosphate significantly decreased by adding nanoparticles (P
< 0.05) while there was no statistical difference in zinc polycarboxylate groups (P > 0.05). On the other hand, although incorporating
nanoparticles significantly reduced the compressive strength of zinc phosphate (P < 0.05), it was noticeably improved in zinc
polycarboxylate groups (P < 0.05).
Conclusions: By incorporating 10 wt% of nano zinc oxide into zinc phosphate and zinc polycarboxylate cements, their compressive
strength are more affected rather than their setting time, film thickness, and acid erosion resistance