Kit of parts for producing a glass ionomer cement, process of production and use thereof

1. 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.-%;

an 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 metal oxides, metal hydroxides, hydroxyapatite, aluminosilicate glasses, fluoroaluminosilicate glasses and mixtures thereof; and

a 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; and

Paste B comprising:

water in an amount from 7 to 20 wt.-%;

a polyacid in an amount from 3 to 70 wt.-%;

a complexing agent in an amount from 0.1 to 12 wt.-%; and

a 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, kaolin, silica, alumina, titania, zirconia and mixtures thereof;

wt.-% with respect to the weight of the respective Paste A or Paste B,

wherein neither Paste A nor Paste B comprising polymerizable component(s) in an amount above 1 wt.-% with respect to the weight of the composition obtained when mixing Paste A and Paste B.

2. The kit of parts of claim 1 , the water content of Paste A being lower than the water content of Paste B.

3. The kit of parts of claim 1 , the non acid-reactive filler A being characterized by the following feature:

pH value of a dispersion of 1 g filler stirred in 10 ml de-ionized water for 5 minutes: between 4 and 7.

4. The kit of parts of claim 1 , the non acid-reactive filler B being characterized by the following feature:

pH value of a dispersion of 1 g filler stirred in 10 ml de-ionized water for 5 minutes: between 4 and 7.

5. The kit of parts of claim 1 , the acid-reactive inorganic filler C being characterized by the following feature:

pH value of a dispersion of 1 g filler stirred in 10 ml de-ionized water for 5 minutes: between 6 and 10.

6. The kit of parts of claim 1 , the acid-reactive inorganic filler C the 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.

7. The kit of parts of claim 6 , Paste A being characterized by at least one or more of the following parameters:

viscosity: from 200 to 50,000 at 28° C., measured at a shear rate of 1 s −1 ;

density: from 1.9 to 2.8 g/cm 3 ;

pH value: from 7 to 10 determined with a pH electrode for 1 g Paste A dispersed in 10 ml de-ionized water and stirred for 5 minutes.

8. The kit of parts of claim 1 , Paste B being characterized by at least one or more of the following parameters:

viscosity: from 1,000 to 50,000 at 28° C., measured at a shear rate of 1 s −1 ;

density: from 1.5 to 2.0 g/cm 3 ;

pH value: from 1 to 4 determined with a pH electrode for 1 g of Paste B dispersed in 10 ml de-ionized water and stirred for 5 minutes.

9. The kit of parts of claim 1 , neither Paste A nor Paste B comprising at least one or more or all of the following components:

polymerizable component(s) in an amount above about 1 wt.-%;

initiator component(s) suitable to cure polymerizable component(s) in an amount above 1 wt.-%;

inhibitior(s) in an amount above 1 wt.-%;

desiccant(s) in an amount above 1 wt.-%, wt.-% with respect to the weight of the respective Paste A or Paste B.

10. A hardened composition for dental use, the hardened composition being obtainable by mixing Paste A and Paste B of the kit of parts described in claim 1 to obtain a mixture, and letting the mixture harden, the hardened composition being characterized by at least one or more of the following parameters:

Flexural strength: above 20 MPa determined according to EN-ISO 9917-2:2010;

Compressive strength: above 100 MPa determined according to EN-ISO 9917-1/2007.

11. A device for storing the kit of parts described in claim 1 , the device comprising two compartments, Compartment A and Compartment B, Compartment A containing Paste A and Compartment B containing Paste B, Compartment A and Compartment B both comprising a nozzle or an interface for receiving an entrance orifice of a static mixing tip.