In vitro evaluation of the enhancement of glass ionomer cement features by using chitosan and nanodiamond

This study investigated the influence of chitosan and nanodiamond incorporation on the surface, optical, and mechanical properties of glass ionomer cement. Total 56 samples (5 mm diameter and 2 mm thickness) were prepared and divided into 4 groups according to the incorporation of chitosan and nanodiamond on Fuji II glass ionomer cement: Control group: no incorporation; 10%CH group: incorporation of 10% chitosan; 10%ND group: incorporation of 10% of nanodiamond; 5%CH-5%ND group: incorporation of 5% chitosan and 5% nanodiamond (n=14). Analyses of color stability, surface roughness, fluorescence intensity, microhardness, morphology, and chemical composition were investigated. Additionally, water sorption, hygroscopic expansion, contact angle, surface free energy, and total free energy of interaction were also assessed. After the initial readings, the samples were individually stored in red wine solution for 28 days. Data were subjected to ANOVA followed by Tukey´s test (α=.05). Aging in wine solution altered the optical, mechanical, and surface properties of glass ionomer cement regardless of the incorporation of the compound (P<.05). 10% chitosan-incorporated glass ionomer cement promoted higher color alteration, surface roughness, and water sorption after aging (P<.05). 10% nanodiamond-incorporated glass ionomer cement showed higher microhardness compared to the other groups before aging (P<.05), however there were no differences among them after aging (P>.05). In general, no differences between the 5% chitosan- and 5% nanodiamond-incorporated glass ionomer cement and control groups were noted on the evaluated analyses (P>.05). Thus, the incorporation of 5% chitosan and 5% nanodiamond is a satisfactory alternative for maintain the surface, optical, and mechanical properties of the glass ionomer cement.