Effect of ultrasound on the setting characteristics of glass ionomer cements studied by Fourier transform infrared spectroscopy.
OBJECTIVE
To investigate the effect of ultrasound (US) application, US staring time and US duration on the setting of glass ionomer cement (GIC) by using Attenuated Total Reflectance Fourier Transform Infrared (ATR/FTIR) spectrometer.


METHODS
Two conventional GICs, Fuji IX Fast and Ketac Molar were studied. US application was started at 30 s or 40 s after mixing and was applied for times between 15 and 55 s on samples of two different thicknesses. The samples were analysed using ATR/FTIR.


RESULTS
US accelerated the curing process in both cements, US needed to be applied for more than 15 s. Both Fuji IX and Ketac Molar showed increased setting on increasing the US application duration from 15 s to 55 s. Increased setting of the GICs was produced when US application started 40 s after mixing rather than 30 s after mixing.


CONCLUSIONS
The significant findings of the study include that US application accelerated the setting processes, by accelerating the formation of the acid salts. The salt formation increased with increase time of US application. The effect of application of US to setting GICs is influenced by time of the start of application of the US. The effects appear to material specific, with Ketac Molar showing a greater effect than Fuji IX.
Talal
A
A
Department of Materials, Queen Mary University of London, London, E1 4NS, UK. atalal@eng.gla.ac.uk
Tanner
K E
KE
Billington
R
R
Pearson
G J
GJ
D005899:Glass Ionomer Cements / Q000737:chemistry*; D006801:Humans; D066298:In Vitro Techniques; D008422:Materials Testing; D017550:Spectroscopy, Fourier Transform Infrared; D013997:Time Factors; D014465:Ultrasonics
D005899:Glass Ionomer Cements; C110713:fuji IX; C110712:ketac-molar