CERAMIC BLANK FILLED WITH AN ORGANIC COMPOUND AND WITH IMPROVED MACHINING PROPERTIES

Abstract

The invention relates to a dental ceramic blank, in particular a filled milling blank, comprising at least one organic Compound, such as a polymer polymerized in the blank, for improving the machining properties of the blank. The blank has an open-pore ceramic microstructure which has 2 to 50 wt. %, based on the total composition of the dental ceramic blank, of at least one organic Compound. The invention also relates to a method for producing the blank. The milling blank according to the invention clearly exhibits improved material properties compared to unfilled purely ceramic milling blanks which have been milled into blanks for molded prosthetic parts in CAD/CAM methods

Claims

1. A dental ceramic blank comprising at least one organic compound, wherein the dental ceramic blank comprises an open-pored ceramic scaffold comprising zirconium dioxide, aluminum oxide, a mixed oxide comprising zirconium dioxide, and/or silicon carbide and comprises from 2 to 50% by weight of at least one organic compound based on the total composition of the dental ceramic blank, and further wherein the at least one organic compound is selected from the group consisting of: (a) at least one polymerizable monomer and/or mixture of polymerizable monomers, wherein the monomer is selected from mono-functional monomers comprising 2 hydroxyethyl methacrylate (HEMA, glycol methacrylate), alkyl methacrylate, (methyl) methacrylate and/or at least one di-, tri-, tetra- or multi-functional monomer 1,4 butanediol dimethacrylate (1,4-BDMA) or pentaerythritol tetraacrylate, bis GMA monomer (bisphenol-A glycidyl methacrylate), triethylene glycol dimethacrylate (TEGDMA) and diethylene glycol dimethacrylate (DEGMA), tetraethylene glycol di(meth)acrylate, propoxylated neopentyl glycol diacrylate, alkyldiol di(meth)acrylate with C2 to C15 in the alkyl group, decanediol di(meth)acrylate, dodecanediol di(meth)acrylate, hexyldecanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate as well as butanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, ethoxylated/propoxylated bisphenol-A di(meth)acrylate, tris(2-hydroxyethyl)-isocyanurate triacrylate, urethane (meth)acrylate, as bis(methacryloxy-2-ethoxycarbonylamino)-alkylene, with alkylene from 2 to 15 C-atoms, UDMA, a mixture containing at least one of said (meth)acrylates; (b) polymers obtainable by polymerization of at least one of the aforementioned monomers or of a mixture comprising at least two of the aforementioned monomers; and (c) a wax, wherein the wax comprises a dental wax comprising paraffin, ceresin, carnauba wax, cacao butter, beeswax, stearic acid, and/or a microcrystalline, paraffinic hydrocarbon wax.

2-4. (canceled)

5. The dental ceramic blank of claim 1, wherein the dental ceramic blank comprises 5 to 25% by weight of at least one organic compound based on the total composition.

6. The dental ceramic blank of claim 1, wherein the dental ceramic blank is a white, green body or hot-isostatically pressed (HIP) blank.

7. The dental ceramic blank of claim 1, wherein the dental ceramic blank has a fracture strength of greater than or equal to 41 N/mm.sup.2 and/or an E-modulus of greater than or equal to 37 kN/mm.sup.2, measured by 4-point bending test DIN EN ISO 6872:2008.

8. The dental ceramic blank of claim 1, wherein the dental ceramic blank is suitable for the production of at least one prosthetic dental or medical blank of a molded part in a material-removing process comprising milling, drilling,. and/or cutting processing and/or material-removing processing employing a laser.

9. The dental ceramic blank of claim 1, wherein the open-pored ceramic scaffold has an open-pored porosity of 10 to 80.

10. A method for producing the dental ceramic blank of claim 1, the method comprising: (a) contacting a dental ceramic blank comprising an open-pored ceramic scaffold comprising zirconium dioxide, aluminum oxide, or a mixed oxide comprising zirconium dioxide and/or silicon carbide with at least one liquid organic compound or organic compound being depositable from gaseous phase, the at least one organic compound selected from: (i) at least one polymerizable monomer and/or mixture of polymerizable monomers, wherein the monomer is selected from mono-functional monomers comprising 2 hydroxyethyl methacrylate (HEMA, glycol methacrylate), alkyl methacrylate, (methyl) methacrylate and/or at least one di-, tri-, tetra- or multi-functional monomer 1,4 butanediol dimethacrylate (1,4-BDMA) or pentaerythritol tetraacrylate, bis GMA monomer (bisphenol-A plycidyl methacrylate), triethylene glycol dimethacrylate (TEGDMA) and diethylene glycol dimethacrylate (DEGMA), tetraethylene glycol di(meth)acrylate, propoxylated neopentyl glycol diacrylate, alkyldiol di(meth)acrylate with C2 to C15 in the alkyl group, decanediol di(meth)acrylate, dodecanediol di(meth)acrylate, hexyldecanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate as well as butanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, ethoxylated/propoxylated bisphenol-A di(meth)acrylate, tris(2-hydroxyethyl)-isocyanurate triacrylate, urethane (meth)acrylate, as bis(methacryloxy-2-ethoxycarbonylamino)-alkylene, with alkylene from 2 to 15 C-atoms, UDMA, a mixture containing at least one of said (meth)acrylates; (ii) polymers obtainable by polymerisation of at least one of the afore-mentioned monomers or of a mixture comprising at least two of the afore-mentioned monomers; and (iii) wax, wherein the wax comprises a dental wax comprising paraffin, ceresin, carnauba wax, cacao butter, beeswax, stearic acid and/or microcrystalline, paraffinic hydrocarbon waxes; and (b) incorporating 2 to 50% by weight of at least one organic compound or organic compound based on the total composition of the dental ceramic blank into the open-pored dental ceramic scaffold.

11. The method of claim 10, wherein the dental ceramic blank is infiltrated with at least one liquid organic compound or at least one organic compound depositable from gaseous phase is condensed in the blank.

12. The method of claim 10, wherein the open-pored ceramic scaffold of the dental ceramic blank has an open-pored porosity of 10 to 80% and is infiltrated with at least one liquid organic compound or at least one organic compound depositable from gaseous phase is condensed in the blank.

13. (canceled)

14. The method of claim 10, wherein the organic compound is polymerized or the wax is solidified.

15. A dental ceramic blank produced by the method of claim 10.

16-17. (canceled)

18. The dental ceramic blank of claim 6, wherein the dental ceramic blank is a white.

19. The dental ceramic blank of claim 8, wherein the dental ceramic blank is suitable for the production of at least one prosthetic dental or medical blank of a molded part in a material-removing process employing a CAD/CAM-process comprising milling, drilling, and/or cutting processing and/or material-removing processing employing a laser.

20. The dental ceramic blank of claim 9, wherein the open-pored ceramic scaffold has an open-pored porosity of 20 to 70%.

21. The dental ceramic blank of claim 9, wherein the open-pored ceramic scaffold has an open-pored porosity of 20 to 60%.

Description

[0030] In the following, the exemplary embodiments of the invention are explained with reference to schematically illustrated figures and exemplary embodiments, however without limiting the invention. In this context,

[0031] FIG. 1: schematically shows an open pored ceramic scaffold 2 filled with an organic compound 1. The organic compound is pyrolised during sintering at 1000 to 1500 C., such that the open-pored ceramic scaffold substantially remains without organic compound.

[0032] Zirconium oxide in white (white body) state (open porosity) was infiltrated by a curable liquid. For this purpose, different infiltration materials were tested, wherein monomer HEMA was used with 99.5% by weight and Interox TBPEH with 0.5% (liquid peroxide). The largest increase in strength could be achieved with this monomer, as shown by 4-point bending test according to DIN EN ISO 6872:2008.

[0033] A zirconium oxide blank having a diameter of 100 mm and a height of 14 mm was infiltrated with HEMA. Infiltration of the blank is made in a bath of the respective liquid or organic compound until complete saturation of the open-pored ceramic scaffold. The blank was laid into the monomer and subsequently cured at 90 C.

[0034] Infiltration time: 2 h; Curing time at 90 C.: 3 h

TABLE-US-00001 Weight difference: White Infiltrated Blank state white state 1 342.010 g 387.610 g 2 341.776 g 380.559 g Flexural strength according to EN DIN 6872:2008:

EXAMPLE 1

[0035] ZrO.sub.2 translucent white, milled samples

[0036] Unsintered, infiltrated rose

TABLE-US-00002 TABLE 1a Sample Fracture E- thick- Sample strength mod. ness width F max N/ kN/ No. mm mm N mm.sup.2 mm.sup.2 1 3.001 4.004 117.8 73.53 43 2 3.006 4.002 145.8 90.69 60 3 3.006 4.003 127.0 78.98 56 4 3.006 4.002 141.1 87.73 56 5 3.005 4.004 143.3 89.09 57 6 3.000 4.004 123.1 76.58 52 7 3.006 4.005 114.4 71.14 54 8 3.006 4.005 132.7 82.48 52 9 3.006 4.005 134.9 83.87 52 10 3.005 4.006 162.3 100.85 62 11 3.005 4.006 1339 83.26 54 12 3.006 4.004 146.8 91.28 56 13 3.005 4.003 111.0 69.06 51 14 3.005 4.004 169.2 105.28 40

TABLE-US-00003 TABLE 1b Fracture Series F max strength E-mod. n = 14 N N/mm.sup.2 kN/mm.sup.2 X 135.9 84.56 53

EXAMPLE 2

[0037] ZrO.sub.2 translucent white, milled samples.

[0038] Unsintered, infiltrated white

TABLE-US-00004 TABLE 2a Sample Sample F Fracture E-mod. thickness width max strength kN/ No. mm mm N N/mm.sup.2 mm.sup.2 1 3.006 4.005 153.3 95.33 62 2 3.002 4.003 165.0 102.89 59 3 3.006 4.005 164.6 102.35 56 4 3.005 4.005 167.5 104.24 60 5 3.006 4.004 145.2 90.27 58 6 3.006 4.004 163.5 101.68 58 7 3.006 4.006 145.8 90.60 59 8 3.000 4.006 171.3 106.43 58 9 3.006 4.006 125.8 78.17 60 10 3.005 4.005 138.3 86.02 59 11 3.007 4.003 159.5 99.17 59 12 3.003 4.005 133.2 82.97 58 13 3.003 4.005 124.6 77.60 55 14 3.005 4.005 161.4 100.43 54

TABLE-US-00005 TABLE 2b Fracture Series F max strength E-mod. n = 14 N N/mm.sup.2 kN/mm.sup.2 X 151.4 94.15 58

EXAMPLE 3

[0039] ZrO.sub.2 translucent white, milled samples.

[0040] Unsintered, untreated, wax

TABLE-US-00006 TABLE 3a Sample Sample F Fracture E-mod. thickness width max strength kN/ No. mm mm N N/mm.sup.2 mm.sup.2 1 3.026 4.068 76.8 46.42 37 2 3.019 4.070 71.9 43.58 39 3 3.028 4.088 74.5 44.73 39 4 3.026 4.061 74.2 44.88 40 5 3.023 4.063 67.7 41.03 40 6 3.025 4.091 81.7 49.09 40 7 3.040 4.063 81.9 49.09 40 8 3.012 4.065 78.8 47.59 37 9 3.016 4.078 72.0 43.69 38 10 3.021 4.080 67.9 41.02 37 11 3.027 4.083 70.9 42.64 37 12 3.025 4.067 79.8 48.23 35

TABLE-US-00007 TABLE 3b F Fracture E-mod. Series max strength kN/ n = 12 N N/mm.sup.2 mm.sup.2 X 74.8 45.17 38

EXAMPLE 4

Comparative Example (Non-Infiltrated)

[0041] ZrO.sub.2 translucent white, milled samples.

[0042] Unsintered, untreated.

TABLE-US-00008 TABLE 4a Sample Sample F Fracture E-mod. thickness width max strength kN/ No. mm mm N N/mm.sup.2 mm.sup.2 1 3.018 4.068 64.4 39.13 36 2 3.020 4.068 67.9 41.17 35 3 3.021 4.077 67.2 40.64 35 4 3.023 4.070 62.9 38.05 36 5 3.006 4.081 66.9 40.79 36 6 3.019 4.062 66.3 40.26 35 7 3.024 4.062 63.5 38.46 35 8 3.022 4.065 69.7 42.24 35 9 3.014 4.069 65.6 39.96 36 10 3.023 4.067 69.4 42.04 35 11 3.020 4.067 67.3 40.88 35 12 3.015 4.067 62.4 37.96 35 13 3.018 4.072 66.8 40.50 35 14 3.024 4.060 67.7 41.04 35

TABLE-US-00009 TABLE 4b F Fracture E-mod. Series max strength kN/ n = 14 N N/mm.sup.2 mm.sup.2 X 66.3 40.22 35