Cationically hardenable dental composition, process of production and use thereof

1. A hardenable dental composition comprising

component (A) comprising a cationically hardenable compound, wherein component (A) has on average at least 2 aziridino groups or more and a molecular weight of at least about 500,

component (B) comprising an initiator being able to initiate the hardening reaction of the cationically hardenable compound, and

component (C) comprising a filler,

wherein the filler comprises a filler body and a filler surface, the filler surface comprising side groups with polar moieties, the polar moieties being attached to the filler surface by a silane coupling agent being characterized by the following formula

A m -B—Si(R 1 ) n (OR 2 ) 3-n

wherein

A represents a polar moiety,

B represents a spacer group,

R 1 represents an alkyl group or an aryl group, and

R 2 represents an alkyl group,

with m=1, 2, 3 or 4 and n=0, 1 or 2;

wherein the polar moieties are selected from thioles, phosphines, amines, amide, urethanes, thiiranes and combinations thereof; and

wherein the hardenable dental composition is characterized by the following parameter after hardening: Tensile Strength (according to DIN 53504): at least about 3.2 MPa.

2. The dental composition according to claim 1 , wherein the filler body comprises quartz, cristobalite, silicates, mixtures and combinations thereof.

3. The dental composition according to claim 1 , wherein the particle size of the filler (d50 value) is within a range from about 0.1 to about 40 μm.

4. The dental composition according to claim 1 , the cationically hardenable compound comprising a hardenable prepolymer, the prepolymer comprising a backbone and reactive side groups, the backbone of the prepolymer comprising moieties selected from polyether, polyesters, polyurethanes and combinations thereof.

5. The dental composition according to claim 1 , the cationically hardenable compound comprising a hardenable prepolymer comprising a backbone and reactive side groups, the reactive side groups being characterized by the following formula

wherein

R represents H, C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkinyl, C7-C15 alkylaryl, C7-C15 arylalkyl or C3-C12 cycloalkyl, and wherein hydrogen atoms can be replaced by Cl or F and/or wherein up to about 5 carbon atoms may be replaced by atoms or group of atoms selected from O, CO, N or S,

E represents a C1-C18 branched or unbranched hydrocarbon chain wherein up to about 5 carbon atoms can be replaced by atoms or group of atoms selected from O, CO, N or S,

G represents a group selected from C(O)O, C(O)NR, C(O), C(O)C(O), C(O)(CH 2 ) m C(O) with m=1 to 10, C(S)NR or CH 2 ,

L represents O, S or NR, with x=0 or 1.

6. The dental composition according to claim 1 , the initiator being selected from components which can be classified as Lewis or Broensted acids, mixtures and combinations thereof.

7. The dental composition of claim 1 further comprising component (D) comprising one or more additive(s) selected from retarders, rheology modifier(s), thixotropic agent(s), diluting agent(s), inhibitor(s), pigment(s), dye(s), plastizer(s), odorous substance(s), flavouring(s), stabilizer(s), mixtures and combinations thereof.

8. The dental composition of claim 7 comprising component (E) comprising at least one surfactant.

9. The dental composition of claim 8 , being characterized by at least one of the following parameters before hardening:

Consistency (according to ISO 4823) of 0, 1, 2 or 3, or

Setting time within about 15 min after mixing at ambient conditions.

10. The dental composition of claim 8 , being characterized by at least one of the following parameters after hardening:

Elongation at break (according to DIN 53504): at least about 150%

Shore Hardness A (according to DIN 53504; after 24 h): at least about 20.

11. A kit of parts or container comprising a base paste and a catalyst paste separated from each other before use, wherein the base paste comprises component (A) and the catalyst paste comprises component (B), and wherein component (C) and the optional components (D) and (E) can be present either in the base paste or the catalyst paste or the base paste and the catalyst paste, and wherein components (A) to (E) are as described in claim 8 .

12. The dental composition according to claim 1 , wherein the polar moieties are amines.