RESUMEN
The purpose of this investigation was to determine the relative erosion/solubility for hybrid glass-ionomers and a compomer using the jet-impingement technique with lactic acid of various molarities. The materials studied included Dyract, Duet, Vitremer, Advance, Fuji-II LC, and Fuji-I, Ketac Cem and Modern Tenacin as the control. Data were analysed using ANOVA and Tukey's comparison test. Results indicated that depth of erosion/solubility with hybrid glass-ionomers and compomers was not measurable by the normal procedure. Similarly, weight changes were not detectable at 0.002, 0.02 and 0.05 M (except for Advance at 0. 05 M). All glass-ionomers materials and the compomer revealed weight changes at 0.1 M after 24 h, in the following increasing order: Dyract < Fuji-II LC=Duet < Advance < Vitremer. It was concluded that weight loss is a better parameter to characterize these new hybrids glass-ionomers and compomers for erosion/solubility by jet-impingement. In addition, a lactic acid of minimum 0.1 M as a test solution is required to generate 24 h-data that can be measured in most laboratories and thus used for statistical comparison.