The present study compared the compressive, tensile and flexural stren
gths of 26 commercial glass ionomer cements, which were evaluated 24 h
after the beginning of the setting reaction. In order to give a globa
l estimation of their overall strength, a coefficient was attributed t
o each glass ionomer cement. This strength coefficient provided a rank
ing of the tested materials. The highest scores were obtained by the r
estorative glass ionomers; however, these materials exhibited lower me
chanical properties than the more classic restorative materials such a
s amalgams or composites. The results also showed a large scattering o
f the mechanical properties among the luting and lining glass ionomer
cements. The creep behavior of the glass ionomer cements was also inve
stigated.