Influence of niobium pentoxide addition on the properties of glass ionomer cements

Abstract

Objective:To determine the influence of niobium pentoxide (Nb2O5) addition on the physicaland chemical properties of glass ionomer cements (GICs).Materials and methods:Five, 10 or 20 wt.% of Nb2O5were incorporated into commercial GICs(Maxxion R, Vitro Molar, Vitro Fil R) and one group of each GIC remained without Nb2O5(controlgroups). The GICs were evaluated by Knoop hardness, compressive strength, acid erosion, par-ticle size and radiopacity. Data were analyzed by two-way ANOVA followed by Tukey's test.Results:The addition of 10% and 20% reduced the microhardness of two GICs (p<.05).Compressive strength showed no difference among groups (p>.05). Nb2O5did not influenceMaxxion R and Vitro Fil R regarding the acid erosion test (p>.05). Vitro Molar increased its aciderosion with 10% of Nb2O5(p<.05). Maxxion R presented 15.78lm, while Vitro Molar and VitroFil R showed 5.14lm and 6.18lm, respectively. As the Nb2O5concentration increased, the radi-opacity increased for all groups. Vitro Molar and Vitro Fil R did not present significant differenceto at least 1 mm aluminum (p>.05).Conclusion:The addition of 5 wt.% Nb2O5did not affect the tested physical and chemical prop-erties of the GICs and improved the radiopacity of one of the cements. These materials aretherefore suitable for further testing of biomimetic remineralization properties.