Abrasionsbeständigkeit konventioneller und lichthärtender Glasionomerzemente

Objectives The discussion about amalgam and the increased awareness of aesthetic appeal required the application of improved restorative materials in dentistry. Alternative materials to amalgam, like tooth coloured composites or glass-ionomer cements (GIC) are constantly refined and merchandised. Glassionomer cements play an important role in the restorative dentistry for several decades. To resist the daily stresses in oral environment as long as possible there are high demands on these materials. The purpose of this study was to investigate the behaviour of wear of conventional and light curing glassionomer cements. The obtained values for these materials will be presented in comparison to amalgam as reference material. Materials and methods For the in-vitro determination of wear behaviour the three-medium-wear test machine ACTA was chosen. Seven conventional and five light curing glassionomer cements were tested with this arrangement and amalgam was applied as reference material. Altogether 13 ACTA-wheels were fabricated. After a four week water storage every wheel performed a run of 200.000 cycles in the ACTA-machine. Afterwards replicas of the test wheels were taken and the depth of wear was evaluated with the confocal laser scanning microscope. Additionally the behaviour of the wear of conventional Fuji® IX GP Extra and its further development Equia™ (Fuji® IX GP Extra with a nano-filled coat G-Coat® Plus) was compared. For this purpose, the values of abrasion after each 10.000 cycle were recorded. By using the ANOVA test and a pairwise comparison with a following Post-Hoc-test (p < 0.05) a statistical evaluation of the values was carried out. Before and after running the test the sample surfaces were analysed in respect to morphological aspects both with the stereo and the scanning electron microscope. Results In this test series a light curing glass-ionomer cement, which was prepared by mixing of a paste-paste system and which showed the minimal porosity, achieved the lowest values of the abrasion ...