Hydrogel materials for obturation

1. A method of filling a tooth or root canal, comprising:

identifying a tooth having a cavity or a root canal in need of filling;

positioning a curable mixture within the cavity or root canal; and

curing the curable mixture within the cavity or root canal;

wherein the curable mixture comprises:

(a) a water-soluble acrylate-based monomer, a water-soluble acrylamide-based monomer, a water-soluble chelating monomer, or a mixture thereof;

(b) a free-radical polymerization initiator;

(c) a radiopaque material; and

(d) an aqueous carrier having a pH in the range of about 7.0 to about 8.4;

wherein the ingredients (a), (b), (c), and (d) are selected to provide the curable mixture with properties suitable for use as a tooth filling after curing of the curable mixture to form a cured mixture by a polymerization of ingredient (a) that is initiated by ingredient (b).

2. The curable mixture of claim 1 , wherein the free radical polymerization initiator is selected from the group consisting of a light initiator, a thermal initiator, and combinations thereof.

3. The curable mixture of claim 1 , wherein the water-soluble acrylamide-based monomer is selected from the group consisting of 3-acrylamidopropyl trimethylammonium chloride, 3-methacrylamidopropyl trimethylammonium chloride, 3-acrylamidopropyl trimethylammonium methyl sulfate, 3-methacrylamidopropyl trimethylammonium methyl sulfate, combinations thereof.

4. The curable mixture of claim 1 , wherein the water-soluble acrylate-based monomer is selected from the group consisting of [2-(methacryloyloxy)ethyl] trimethylammonium chloride, [2-(acryloyloxy)ethyl] trimethylammonium chloride, [2-(acryloyloxy)ethyl] trimethylammonium methyl sulfate, [2-(methacryloyloxy)ethyl] trimethylammonium methyl sulfate, (hydroxyethyl)methacrylate (HEMA), poly(ethylene glycol) diacrylate, ethoxylated trimethylolpropane triacrylate, and combinations thereof.

5. The curable mixture of claim 1 , wherein the chelating monomer is selected from the group consisting of 4-methacryloxyethyl trimellitic acid (4-MET), glycerol phosphate dimethacrylate (GPDM), and combinations thereof.

6. The curable mixture of claim 1 , wherein the radiopaque material is selected from the group consisting of a polymerizable radiopaque monomer, a radiopaque salt, and combinations thereof.

7. The curable mixture of claim 6 , wherein the radiopaque material is selected from the group consisting of sodium diatrizoate hydrate, iodophenyl functionalized polyethylene glycol, a water soluble radiopaque aromatic acid derived (meth)acrylate, and combinations thereof.

8. The curable mixture of claim 7 , wherein the water soluble radiopaque aromatic acid derived (meth)acrylate is 5-acrylamido-2,4,6 triiodo isophthalic acid.

9. The curable mixture of claim 1 , further comprising a polymerization cross-linker.

10. The curable mixture of claim 9 , wherein the polymerization cross-linker is selected from the group consisting of N,N′-methylenebis(acrylamide) (MBAA), triethylene glycol dimethacrylate (TEGDMA), and combinations thereof.

11. The curable mixture of claim 2 , wherein the light initiator is selected from the group consisting of camphorquinone (CQ), 7,7-dimethyl-2,3-dioxobicyclo [2.2.1] heptane-1-carboxylic acid (CCQ), 1-phenyl-1,2-propanedione (PPD), 2,2′-azobis[2-methyl-N-(2-hydroxyethyl)propionamide (VA-086), and combinations thereof.

12. The curable mixture of claim 1 , further comprising a co-initiator selected from the group consisting of N-phenylglycine, 2-pyrrolidinone, dimethylaminoethyl acrylate (DMAEA), triethanolamine (TEOA), 1-vinyl-2-pyrrolidone and L-arginine, and combinations thereof.

13. The curable mixture of claim 2 , wherein the thermal initiator comprises 2,2′-azobis[2-(2-imidazolin-2-yl) propane] dihydrochloride.

14. The curable mixture of claim 1 , wherein the free-radical polymerization initiator comprises potassium persulfate and triethanolamine.

15. The curable mixture of claim 1 , further comprising methacrylic acid.

16. The curable mixture of claim 1 , comprising from 20 wt % to 60 wt % of the aqueous carrier, based on the weight of the curable mixture.

17. A method of filling a root canal with a hydrogel polymer, comprising:

identifying a tooth having a root canal in need of filling;

positioning a curable mixture within a handpiece, comprising delivering the curable mixture to the handpiece in two liquid parts;

forming a liquid jet within the handpiece and using the liquid jet to deliver the two parts;

partially curing the curable mixture within the root canal with light energy; and

exposing the partially cured mixture within the root canal to heat to form a cured hydrogel polymer within the root canal;

wherein the curable mixture comprises:

(a) a water-soluble acrylate-based monomer, a water-soluble acrylamide-based monomer, a water-soluble chelating monomer, or a mixture thereof;

(b) a free-radical polymerization initiator;

(c) a radiopaque material; and

(d) an aqueous carrier having a pH in the range of about 7.0 to about 8.4;

wherein the ingredients (a), (b), (c), and (d) are selected to provide the curable mixture with properties suitable for use as a tooth filling after curing of the curable mixture to form a cured mixture by a polymerization of ingredient (a) that is initiated by ingredient (b).

18. A curable mixture of ingredients, comprising:

(a) 20 wt. % to 50 wt % poly(ethylene glycol) diacrylate (PEG);

(b) 0.5 wt % to 1.5 wt. % N,N′-methylenebis(acrylamide) (MBAA);

(c) 0.2 wt. % to 1.5 wt % potassium persulfate;

(d) 0.2 wt. % to 0.6 wt % triethanolamine;

(e) 5 wt % to 30 wt. % of 5-acrylamido-2,4,6-triiodo isophthtalic acid; and

(f) 20 wt % to 60 wt % of an aqueous carrier,

wherein the ingredients are selected to provide the curable mixture with properties suitable for use as a tooth filling after curing of the curable mixture to form a cured mixture.

19. A curable mixture of ingredients, comprising:

(a) 0.1 wt % to 0.5 wt % 2,2′-azobis[2-(2-imidazolin-2-yl) propane] dihydrochloride;

(b) 20 wt % to 50 wt % ethoxylated trimethylolpropane triacrylate;

(c) 10 wt % to 15 wt % poly(ethylene glycol) diacrylate (PEG);

(d) 5 wt % to 35 wt % 5-acrylamido-2,4,6-triiodo isophthalic acid; and

(f) 15 wt % to 50 wt % water.

20. A curable mixture of ingredients, comprising:

(a) 0.1 wt % to 0.5 wt % 2,2′-azobis[2-(2-imidazolin-2-yl) propane] dihydrochloride;

(b) 0.1 wt % to 2.5 wt % of a light cure initiator;

(c) 10 wt % to 30 wt % poly(ethylene glycol) diacrylate;

(d) 0.5 wt % to 2 wt % N,N′-methylenebis (acrylamide) (MBAA);

(e) optionally, 0.1 wt % to 1 wt % [2-(acryloyloxy)ethyl] trimethyl-ammonium chloride; and

(f) an aqueous carrier,

wherein the ingredients are selected to provide the curable mixture with properties suitable for use as a tooth filling after curing of the curable mixture to form a cured mixture.

21. A curable mixture of ingredients, comprising:

(a) 20 wt % to 50 wt % ethoxylated trimethylolpropane triacrylate;

(b) 10 wt % to 15 wt % poly(ethylene glycol) diacrylate;

(c) 0.1 wt % to 3 wt % 2,2′-azobis[2-methyl-N-(2-hydroxyethyl)propionamide;

(d) 5-acrylamido-2,4,6-triiodo isophthalic acid; and

(e) 15 wt % to 55 wt % aqueous carrier;

wherein the ingredients are selected to provide the curable mixture with properties suitable for use as a tooth filling after curing of the curable mixture to form a cured mixture.

22. A method of filling a tooth or root canal, comprising:

identifying a tooth having a cavity or a root canal in need of filling;

positioning the curable mixture of claim 18 within the cavity or root canal; and

curing the curable mixture within the cavity or root canal.

23. A method of filling a tooth or root canal, comprising:

identifying a tooth having a cavity or a root canal in need of filling;

positioning the curable mixture of claim 19 within the cavity or root canal; and

curing the curable mixture within the cavity or root canal.

24. A method of filling a tooth or root canal, comprising:

identifying a tooth having a cavity or a root canal in need of filling;

positioning the curable mixture of claim 20 within the cavity or root canal; and

curing the curable mixture within the cavity or root canal.

25. A method of filling a tooth or root canal, comprising:

identifying a tooth having a cavity or a root canal in need of filling;

positioning the curable mixture of claim 21 within the cavity or root canal; and

curing the curable mixture within the cavity or root canal.