COMPARISON OF THE COMPRESSIVE STRENGTH OF CONVENTIONAL AND RESIN-MODIFIED GLASS IONOMER CEMENTS

Abstract

Introduction: Glass ionomer cements have many advantages as restorative materials: adhesion to the tooth structure, fluoride releasing capacity, biocompatibility. However, their mechanical properties are not as desirable as they should be for the conventional glass ionomers, questioning their use as a restorative material. Aim: The aim of this study was to compare the compressive strength of two encapsulated commercial glass ionomer cements – a conventional glass ionomer (Riva Self Cure) and a resin-modified glass ionomer cement (Riva Light Cure). Materials and methods: Six conventional and six resin-modified glass ionomer cement specimens were prepared and kept in 10ml of deionised water at 37°C for 24 hours and 28 days. The specimens (after 24 hours and 28 days) were loaded in an Instron mechanical testing machine in compression until failure. A crosshead speed of 1mm/min and load cell of 30kN was used to conduct the compressive strength test. Results: Resin-modified glass ionomer cement showed greater compressive strength values after 24 hours and 28 days than conventional glass ionomers. The compressive strength of both cements increased from 24 hours to 28 days, with conventional glass ionomers showing a greater change over the time period. Conclusion: Resin-modified glass ionomer cements have greater compressive strength properties than conventional glass ionomers. This suggests that the cross-linked polymer matrices have higher strengths than gel network formed by acid-base reactions in conventional glass ionomers.

Keywords

• conventional glass ionomer cement
• resin-modified glass ionomer cement
• compressive strength