Effect of addition of chitosan on water sorption, solubility and microhardness of glass ionomer cement

Abstract

Background A glass ionomer cement (GIC) restorative materials is commonly used in dentistry for permanent cementation of indirect restorations, liner, base or as atraumatic restorative treatment for the restoration of primary teeth, especially in developing countries. Water sorption and solubility of dental cement could be a primary cause of restoration failure. Early moisture contamination on luting cements during setting results not only in an increased loss of substance but also a reduction of physical properties especially its surface hardness. Chitosan can improve the mechanical properties of GICs and decrease its solubility, therefore it is necessary to do research on the solubility, water sorption and surface hardness of the chitosan modified GICs. Aim This study was aimed to investigate the effect of addition of chitosan to the liquid of GIC on water sorption, solubility and microhardness of GIC. Materials and methods Commercially available powder/liquid restorative GIC was used in this study. A total of 60 samples were used in this study. The GIC samples was divided into samples of conventional GIC as a control (group I), GIC modified with 25% (v/v) chitosan solution (group II) and GIC modified with 50% (v/v) chitosan solution (group III). Water sorption and solubility results obtained from the difference between the weights of samples before and after immersion in an incubator and after dehydration. The samples with 6 mm diameter and 3 mm thickness were used for Vickers microhardness test. Results were subjected to analysis of variance and Tukey's test. Results The addition of chitosan to GIC may increase water sorption of GIC and decreased its solubility. The addition of chitosan to GIC significantly decreased its surface hardness. Conclusion The modification of GIC liquid with chitosan showed to be more effective in decreasing the solubility of GIC. However, the microhardness may significantly decrease with chitosan incorporation in polyacrylic acid liquid.