Kit of parts containing a cationically hardenable composition and use as dental retraction material

1. A kit of parts for preparing a dental retraction composition, the kit of parts comprising:

a Base Paste (B) comprising a cationically hardenable component, the cationically hardenable component comprising a polyether polymer comprising cationically curable side groups,

a Catalyst Paste (C) comprising a starter component selected from Lewis acids, Brønsted acids, precursors of Lewis acids, and components which can be activated by radiation to produce a Lewis acid, salts and mixtures thereof,

a porous water-adsorbing component selected from molecular sieves, zeolites, silica gel, and mixtures thereof, and

water;

wherein:

the porous water-adsorbing component is present in Base Paste (B) and the water is present in Catalyst Paste (C), or

the porous water-adsorbing component is present in Catalyst Paste (C) and the water is present in Base Paste (B).

2. The kit of parts of claim 1 , the ratio of porous water-adsorbing component to water being from 1.00:0.50 to 1.00:0.05 with respect to weight.

3. The kit of parts of claim 1 , the porous water-adsorbing component being characterized by one or more of the following features:

having a BET surface area of at least 200 m 2 /g;

average pore diameter: below 100 nm;

average particle size: from 1 to 50 μm; and

pH value: above 7.

4. The kit of parts of claim 1 , the cationically hardenable component being characterized by at least of the following features:

the cationically curable side groups being aziridino groups;

being present in an amount from 5 to 90 wt.-% with respect to the weight of a composition obtained by combining Base Paste (B) and Catalyst Paste (C).

5. The kit of parts of claim 1 , the starter component being characterized by at least of the following features:

being water-soluble;

being present in an amount from 1 to 30 wt.-% with respect to the weight of a composition obtained by combining Base Paste (B) and Catalyst Paste (C).

6. The kit of parts of claim 1 , at least one of Base Paste (B) and Catalyst Paste (C) having a consistency of less than 28 mm determined according to ISO 4823.

7. The kit of parts of claim 1 , Catalyst Paste (C) further comprising an antacid compound.

8. A composition obtained by mixing Base Paste (B), and Catalyst Paste (C) of claim 1 , the composition being characterized by one or more of the following features:

consistency: less than 26 mm determined according to ISO 4823;

Shore hardness A: from 40 to 90 determined according to DIN 53505 24h after mixing; and

hardening within 15 min within a temperature range from 20 to 40° C. to a rubber elastic mass.

9. The composition of claim 8 , comprising the components in the following amounts:

cationically hardenable component: 5 to 90 wt.-%,

starter component: 1 to 30 wt.-%,

porous water-adsorbing component: 1 to 60 wt.-%, and

water: 0.01 to 10 wt.-%,

wt.-% with respect to the weight of the composition.

10. The composition of claim 8 , being characterized by one or more as follows:

the cationically hardenable component comprising an aziridino moiety and being present in an amount from 15 to 80 wt.-%,

the starter component selected from Brønsted acids or Lewis acids and being present in an amount from 2 to 20 wt.-%,

the water-adsorbing component being present in an amount from 2 to 20 wt.-%, and

water being present in an amount from 0.1 to 5 wt.-%,

wt.-% with respect to the weight of the composition.

11. A method for preparing a dental retraction material, the method comprising:

contacting the Base Paste (B) and the Catalyst Paste (C) of claim 1 .

12. A process for taking a dental impression including sub-gingival parts, the process comprising:

combining the Base Paste (B) and Catalyst Paste (C) of claim 1 to form a dental composition (I),

applying the dental composition (I) to a dental tissue,

allowing the dental composition (I) to harden,

applying a dental composition (II) in contact with dental composition (I), and

removing together the dental composition (II) and the dental composition (I) from the dental tissue,

wherein the dental composition (I) and dental composition (II) are comprised of different materials.

13. The kit of parts of claim 1 , wherein the combination of the water-adsorbing component and water is effective to increase the consistency, according to ISO 4823, of the hardenable composition.

14. A composition for dental retraction obtained by mixing the Base Paste (B) and the Catalyst Paste (C) of claim 1 .

15. A kit of parts for conducting a dental retraction, the kit of parts comprising the Base Paste (B) and the Catalyst Paste (C) of claim 1 ,

wherein:

the Base Paste (B) comprises the porous water-adsorbing component, and

the Catalyst Paste (C) comprises water.

16. The kit of parts of claim 7 , wherein the antacid is selected from oxides, hydroxides, carbonates, or carboxylates of Zn or Al, or a combination thereof.

17. The kit of parts of claim 1 , the polyether polymer being a copolymer of ethylene oxide and tetrahydrofuran.

18. The kit of parts of claim 17 , the cationically curable side groups being aziridine groups.

19. The kit of parts of claim 1 , further comprising a non-ionic surfactant.

20. The kit of parts of claim 1 , further comprising one or more of a retarder, a pigment, and a filler.