Two-component self-adhesive dental composition, storage stable initiator system, and use thereof

1. A kit of parts for dental use comprising Part A and Part B,

Part A comprising:

component(s) comprising an ascorbic acid moiety,

stabilizer selected from sulphite(s), phosphite(s) or mixtures thereof,

optionally polymerizable component(s) without acidic moieties,

optionally polymerizable component(s) with acidic moieties,

optionally filler(s),

optionally additive(s), and

Part B comprising:

polymerizable component(s) without acidic moieties,

polymerizable component(s) with acidic moieties,

transition metal component(s),

organic peroxide(s),

optionally filler(s),

optionally additive(s).

2. The kit of parts of claim 1 ,

Part A comprising:

component(s) comprising an ascorbic acid moiety,

stabilizer selected from sulphite(s), phosphite(s) or mixtures thereof,

polymerizable component(s) without acidic moieties,

filler(s),

optionally polymerizable component(s) with acidic moieties,

optionally additive(s), and

Part B comprising:

polymerizable component(s) without acidic moieties,

polymerizable component(s) with acidic moieties,

transition metal component(s),

organic peroxide(s) selected from hydroperoxide(s) and di-peroxide(s),

filler(s),

optionally additive(s),

wherein the kit of parts is provided as a paste/paste system.

3. The kit of parts of claim 1 , wherein the ascorbic acid moiety and the stabilizer are present in an ascorbic acid: stabilizer ratio between 1:5 to 5:1 with respect to mol.

4. The kit of parts of claim 1 , wherein the composition of Part A has a pH value from 6 to 8 if brought in contact with a wet pH sensitive paper and wherein the composition of Part B has a pH value below 4 if brought in contact with a wet pH sensitive paper.

5. The kit of parts of claim 1 , the organic peroxide(s) represented by the formula R—O—O—H, wherein R is alkyl, branched alkyl, cycloalkyl, alkylaryl, or aryl.

6. The kit of parts of claim 1 , the organic peroxide(s) represented by the formula R 1 —O—O—R 2 —O—O—R 3 , wherein R 1 and R 3 are independently selected from H, alkyl, branched alkyl, cycloalkyl, alkylaryl, and aryl; and R 2 is selected from alkyl and branched alkyl.

7. The kit of parts of claim 1 , the transition metal component comprising a transition metal selected from Ti, V, Cr, Mn, Co, Ni, Cu, Fe, Zn, and a combination thereof, either in hydrated or in dry form.

8. The kit of parts of claim 1 , the stabilizer selected from an organic sulphite, an organic phosphite, and a combination thereof.

9. The kit of parts of claim 1 , Part A or Part B further comprising a photoinitiator.

10. A composition obtained by mixing Part A and Part B of the kit of parts of claim 1 , and curing the resulting mixture to provide the composition,

wherein the composition is self-etching, self-adhesive, and self-curing, and

wherein the composition is for dental or orthodontic use.

11. The kit of claim 1 , wherein the composition obtained immediately after mixing Part A and Part B having a pH value below 7, if brought into contact with wet pH sensitive paper.

12. The composition of claim 10 for use as anterior or posterior filling material, adhesive, cavity liner, flowable, cement, coating composition, root canal filler, root canal sealant, core build-up material or a combination thereof.

13. The composition of claim 10 , the composition comprising the components in the following amounts:

component(s) comprising an ascorbic acid moiety: from 0.01 wt.-% to 5 wt.-%, stabilizer(s) selected from sulphite(s), phosphite(s) and mixtures thereof: from 0.01 wt.-% to 5 wt.-%,

transition metal component(s): from 0.00001 wt.-% to 3 wt.-%,

organic peroxide(s): from 0.01 wt.-% to 5 wt.-%,

polymerizable component(s) without acidic moieties: from 5 wt.-% to 65 wt.-%,

polymerizable component(s) with acidic moieties: from 2 wt.-% to 50 wt.-%,

filler(s): if present from 1 wt.-% to 90 wt.-%,

additives(s): if present from 0.01 wt.-% to 15 wt.-%,

wt.-% with respect to the amount of the whole composition.

14. The composition of claim 10 , not comprising water in an amount of more than 2 wt.-% with respect to the weight of the whole composition.

15. An initiator system for curing an acidic composition, the initiator system comprising:

component(s) comprising an ascorbic acid moiety, stabilizer selected from sulphite(s), phosphite(s) and mixtures thereof, transition metal component(s), and

peroxide(s); and the acidic composition comprising polymerizable component(s) with acidic moieties.

16. The kit of parts of claim 7 , the transition metal component selected from copper acetate, copper chloride, copper benzoate, copper acetylacetonate, copper naphthenate, copper carboxylates, copper bis(1-phenylpentan-1,3-dione), copper complexes, and a combination thereof, either in hydrated or in dry form.

17. The kit of parts of claim 9 , the photoinitiator comprising a sensitizer and a further reducing agent, wherein the further reducing agent is different from the component comprising the ascorbic acid moiety.