Effect of ultrasonic excitation on the porosity of glass ionomer cement: A scanning electron microscope evaluation

Background: Ultrasonic excitation (US) was applied to glass ionomer cement (GIC) during early set time to increase the advantageous properties of this material. Purpose: The aim of this in vitro study was to assess the inner porosity of GIC after US. Study design: A total of 16 specimens, for each material, were prepared from high‐viscosity GIC Fuji IX GP, Ketac Molar, and Ketac Molar Easymix. Half of these specimens ( n = 8) received 30 s of US during the initial cement setting. After completion of the material setting, specimens were fractured and observed by scanning electronic microscopy to quantitatively assay porosity inside the material using Image J software. Results: Statistical data analysis revealed that US reduced the porosity for all tested materials ( P ≤ 0.05). The following reductions (expressed in percentages) were achieved: Fuji IX—from 3.9% to 2.8%; Ketac Molar Easy Mix—from 4.4% to 2.6%, and Ketac Molar—from 2.4% to 1.6%. Conclusion: Under the tested conditions, US was an effective method for porosity reduction inside the material. Microsc. Res. Tech. 74:54‐57, 2011. © 2010 Wiley‐Liss, Inc.