Microhardness and Surface Roughness of Glass Ionomer Cements after APF and TiF4 Applications

Objective: To evaluate whether TiF₄ solution and APF gel had any adverse effects on the surface morphology of newly developed glass ionomers. Study Design: Fifteen disc-shaped specimens of Fuji IX Extra, Fuji II LC and Ketac N100 were prepared and stored in 2 ml of artificial saliva at 37°C for 8 weeks. Specimens of each material were divided randomly into three subgroups as 1 and 4 minutes application of 1.23% APF gel and 1 minute application of 1% TiF₄ solution. Specimens were reaged for another 8 weeks. Microhardness, surface roughness values and surface morphology were evaluated by using Vicker's hardness test, surface profilometry and scanning electron microscopy (SEM) for all time interventions, respectively. One-way Anova test was performed and differences were compared by Tukey's HSD and Dunnet T3 test. Results: APF and TiF₄ applications decreased microhardness significantly in Fuji II LC. In Fuji IX Extra microhardness decreased significantly after 1- and 4-min APF applications. Ketac N100 showed no difference in microhardness after APF and TiF₄ applications. Surface roughness was not affected at any time interval for three restorative materials. Conclusion: Within the limitations of this vitro study, it was revealed that, potential adverse effects of APF and TiF₄ applications might be material dependant. Hence, restorative materials should be selected in accordance with kind, frequency and application time of fluoridation to avoid deteriorations of the restorations.

microhardness, surface roughness, APF, TiF4

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