A kit of parts for preparing a glass ionomer composition for dental use, the kit comprising: a Paste A and a Paste B, Paste A comprising water in an amount from 5 to 18 wt.-%, acid-reactive inorganic filler C in an amount from 20 to 90 wt.-%, the acid-reactive inorganic filler C having a mean particle size in the range from 3 to 10 μm and being selected from basic metal oxides, metal hydroxides, hydroxyapatite, aluminosilicate glasses, fluoroaluminosilicate glasses, glasses having a Si/Al ratio by wt.-% of below 1.5 and mixtures thereof, non acid-reactive filler A in an amount from 1 to 50 wt.-%, the non acid-reactive filler A having a mean particle size in the range from 10 nm to 500 nm and being selected from silica, alumina, titania, zirconia and mixtures thereof, Paste B comprising water in an amount from 7 to 20 wt.-%, polyacid in an amount from 3 to 70 wt.-%, complexing agent in an amount from 0.1 to 12 wt.-%, non acid-reactive filler B in an amount from 5 to 60 wt.-%, the non acid-reactive filler B having a mean particle size in the range from 1 to 10 μm and being selected from quartz, nitrides, kaolin, borosilicate glass, strontium oxide based glass, barium oxide based glass, silica, alumina, titania, zirconia and mixtures thereof, wt.-% with respect to the weight of the respective Paste A or Paste B, the water content of the composition obtained when mixing Paste A and Paste B being below 20 wt.-%, neither Paste A nor Paste B comprising polymerizable component(s) in an amount above 1.0 wt.% with respect to the weight of the composition obtained when mixing Paste A and Paste B. Paste A comprising water in an amount from 5 to 18 wt.-%, acid-reactive inorganic filler C in an amount from 20 to 90 wt.-%, the acid-reactive inorganic filler C having a mean particle size in the range from 3 to 10 μm and being selected from basic metal oxides, metal hydroxides, hydroxyapatite, aluminosilicate glasses, fluoroaluminosilicate glasses, glasses having a Si/Al ratio by wt.-% of below 1.5 and mixtures thereof, non acid-reactive filler A in an amount from 1 to 50 wt.-%, the non acid-reactive filler A having a mean particle size in the range from 10 nm to 500 nm and being selected from silica, alumina, titania, zirconia and mixtures thereof, water in an amount from 5 to 18 wt.-%, acid-reactive inorganic filler C in an amount from 20 to 90 wt.-%, the acid-reactive inorganic filler C having a mean particle size in the range from 3 to 10 μm and being selected from basic metal oxides, metal hydroxides, hydroxyapatite, aluminosilicate glasses, fluoroaluminosilicate glasses, glasses having a Si/Al ratio by wt.-% of below 1.5 and mixtures thereof, non acid-reactive filler A in an amount from 1 to 50 wt.-%, the non acid-reactive filler A having a mean particle size in the range from 10 nm to 500 nm and being selected from silica, alumina, titania, zirconia and mixtures thereof, Paste B comprising water in an amount from 7 to 20 wt.-%, polyacid in an amount from 3 to 70 wt.-%, complexing agent in an amount from 0.1 to 12 wt.-%, non acid-reactive filler B in an amount from 5 to 60 wt.-%, the non acid-reactive filler B having a mean particle size in the range from 1 to 10 μm and being selected from quartz, nitrides, kaolin, borosilicate glass, strontium oxide based glass, barium oxide based glass, silica, alumina, titania, zirconia and mixtures thereof, water in an amount from 7 to 20 wt.-%, polyacid in an amount from 3 to 70 wt.-%, complexing agent in an amount from 0.1 to 12 wt.-%, non acid-reactive filler B in an amount from 5 to 60 wt.-%, the non acid-reactive filler B having a mean particle size in the range from 1 to 10 μm and being selected from quartz, nitrides, kaolin, borosilicate glass, strontium oxide based glass, barium oxide based glass, silica, alumina, titania, zirconia and mixtures thereof,