A comparative evaluation of the microhardness of glass ionomer cements modified with chitosan and chlorhexidine: A 1-year in vitro study

Abstract

Aims and Objectives: Enhancement of the therapeutic properties of glass ionomer cements with antimicrobials, without alterations in its existing physical properties is of current research interest. One such innate property is microhardness. The aim of this study was to compare the microhardness of chlorhexidine-modified glass ionomer cement (CHX GIC) and chitosan-modified glass ionomer cement (CHT GIC) with an unmodified glass ionomer cement (FUJI IX GIC) and to study the variations in their microhardness when stored for a year. Materials and Methods: In an experimental analytic study, Fuji IX GIC liquid was modified with chitosan to form 10% vol/vol of CHT GIC. Fuji IX GIC powder was modified with chlorhexidine diacetate powder to form 1% wt/wt CHX GIC. Fuji IX GIC was used as control. Forty cylindrical samples each of the control and experimental cements were prepared, embedded in resin and stored in distilled water. Vickers microhardness testing was performed at stipulated time periods. The mean and standard deviation of each group were calculated. The data were analyzed using analysis of variance and post hoc Tukey test for multiple comparisons. Results: Materials showed significant difference in microhardness (P <0.000) at all time periods chosen for the study. FUJI IX GIC had the highest microhardness values at all time periods. CHT GIC showed the lowest microhardness and CHX GIC showed excellent stability over time. Conclusion: Although the therapeutic effects of modified GICs are proven, these additives can significantly and negatively alter the existing microhardness of the parent material.