PRINTABLE AND SINTERABLE DENTAL COMPOSITIONS FOR PRODUCING PARTS OF DENTAL PROSTHESES AND METHOD FOR PRODUCING SAME

Abstract

Dental compositions and methods provide a flowable ceramic powder of a powdered component, wherein the compositions and methods comprise at least one dental glass, glass ceramics, metal oxide, mixed oxide selected from metal oxides and/or a mixture comprising at least two of said components, a printable dental ink. Moreover, the compositions and methods produce dental prosthetic form bodies.

Claims

1. A dental Dental composition of a flowable dental ceramic powder suitable for the production of a powder bed for printing, wherein the flowable dental powder contains a powdered component comprising at least one component selected from one dental glass, glass ceramics, metal oxide, mixed oxide selected from metal oxides and a mixture comprising at least two of said components wherein particle sizes of the powdered component are in the range of 2 nm to 200 m.

2. The dental composition according to claim 1, wherein the powdered component comprises at least one component selected from zirconium dioxide, silicon dioxide, mixed oxides of zirconium dioxide and silicon dioxide, precipitated silicic acids, dental aluminosilicate or fluoroaluminosilicate glasses, bariumaluminium silicate, strontium silicate, strontium borosilicate, lithium silicate, lithium disilicate, lithiumaluminium silicate, layered silicates/phyllosilicates, calcium oxide, cerium oxide, potassium oxide, sodium oxide, ytterbium, ytterbium oxide, ytterbium fluoride, borosilicates, borosilicate glasses, zeoliths and a mixture comprising at least one of said components.

3. The dental composition according to claim 1, wherein the powdered components has a particle size of d.sub.90 of less than or equal to 100 micrometre (m).

4. The dental composition according to claim 1, wherein the composition has a bulk density of more than or equal to 0.4 g/cm.sup.3.

5. The dental composition according to claim 1, wherein the composition has an angle of repose of less than or equal to 60.

6. The dental composition according to claim 1, wherein the composition is present as a powder bed.

7. The dental composition according to claim 1, wherein the composition contains at least one excipient comprising at least one selected from flow additives, lubricants, antistatic agents, dispersing agents and binding agents.

8. A printable liquid dental ink, comprising at least one dental powdered component comprising at least component selected from one dental glass, glass ceramics, metal oxide, mixed oxide selected from metal oxides and a mixture comprising at least two of said components, at least one liquid component, and, optionally, at least one excipient selected from a dispersing agent, an anti-drying additive, a flow additive, a peptising agent, a binding agent and an excipient for regulation of the surface tension.

9. The dental ink according to claim 8 wherein the ink has a) a viscosity of 1 to 50 mPa.Math.s, and/or b) a surface tension of less than or equal to 50 mN/m and/or c) the content of powdered components is 0.01 to 50% by weight.

10. The dental ink according to claim 8, wherein the ink comprises 1 to 50% by weight powdered components 1 to 90% by weight liquid component, whereby the liquid component comprises a) 1 to 90% by weight water, and b) 0 to 70% by weight of at least one water-miscible organic diluting agent in the total composition of the liquid component, and 0.001 to 10% by weight of at least one excipient, such as dispersing agent, whereby the total composition of the ink adds up to 100% by weight.

11. The dental Dental ink according to claim 8, wherein the powdered component has particle sizes of less than or equal to 5 m.

12. The dental ink according to claim 8, wherein the ink inorganic coloured pigments.

13. The dental ink according to claim 8, wherein the ink is distributable in droplets with a diameter of 10 to 100 m.

14. The dental ink according to claim 8, wherein the liquid component contains at least one organic diluting agent and/or comprises at least one anti-drying additive such as polyether, polyethylene glycol, polypropylene glycol, EO/PO polyether, ethylene glycol and/or glycin.

15. The dental ink according to claim 13, wherein the droplets can be generated from the ink that have an aspect ratio of diameter 1 to diameter 2 of 0.2 to 5, whereby diameter 1 and diameter 2 are arranged at an angle of approximately 90 with respect to each other.

16. A method of printing three-dimensional form bodies that are suitable for the production at least of parts of dental prostheses, the method comprising the process section (A), including: (i) contacting a dental ink comprising at least one liquid component and at least one dental powdered component, to (ii) at least a part of a layer of a dental ceramic powder, (iii) whereby the contacting causes the dental ceramic powder to be solidified at least at the point of contact at least in said layer of the powder or in the region of the point of contact, (iv) applying another layer of a flowable dental ceramic powder, in particular onto the layer (ii) and (v) performing (i), (ii), (iii), and (iv) at least once.

17. The method according to claim 16, wherein, after process section (A) after repeatedly performing (i) to (v) at least one dental three-dimensional form body is obtainable that corresponds, at least in part, to a blank of a part of a dental prosthetic restoration.

18. The method according to claim 17, wherein the method further comprises a process section (B) including: (I) forming a green body from the form body, and (II) exposing the green body.

19. The method according to claim 18, wherein the method further comprises a process section (C) including: (I) optionally, removing the binding agent from the green body, (II) sintering the green body, and (III) obtaining a three-dimensional dental form body that corresponds to at least a part of a dental prosthetic restoration.

20. The method according to claim 16, wherein at least one layer of a dental ceramic powder having a layer thickness of 0.1 m to 100 m is being applied or present.

21. The method according to claim 16, wherein (iv) the applying of a layer of the flowable ceramic powder takes place by dispensing the ceramic powder from an oscillating bulk cup with an elongated opening provided on the bottom side or over an overflow edge onto the existing layer.

22. The method according to claim 16, wherein, after application of the flowable dental ceramic powder from the bulk cup or during the application of the dental ceramic powder from the bulk cup, a device compacts the dental ceramic powder and forms it into a layer.

23. A kit comprising starting materials for three-dimensional printing at least of parts of dental prostheses, whereby the kit comprises, as separated components, (A) a dental composition of the flowable dental ceramic powder according to claim 1 and, as component (B), a printable liquid dental ink.

24. A powder bed comprising form bodies of prosthetic parts that obtainable according to the method according to claim 16.

25. A dental three-dimensional green body obtainable according to the method according to claim 16.

26. A port of a dental prosthesis or dental prosthesis obtainable according to the method according to claim 16.

27. (canceled)

28. (canceled)

Description

EXAMPLES

Examples 1 to 8Ink

[0113] Ink: The inks were prepared by mixing components (i), (ii), and (iii) with each other, with the sum adding up to 100% by weight. In order to prepare homogeneous dispersions, the samples were after-treated in an ultrasonic bath.

[0114] (i) Filling agent in ink:

[0115] a) Zirconium dioxide stabilised with 3 mol-% Y.sub.2O.sub.3; 15 wt.-% (Example 1)

[0116] b) Zirconium dioxide stabilised with 3 mol-% Y.sub.2O.sub.3; 20 wt.-% (Example 2)

[0117] c) Zirconium dioxide stabilised with 3 mol-% Y.sub.2O.sub.3; 25 wt.-% (Example 3)

[0118] d) Zirconium dioxide stabilised with 3 mol-% Y.sub.2O.sub.3; 30 wt.-% (Example 4)

[0119] e) Zirconium dioxide stabilised with 3 mol-% Y.sub.2O.sub.3; 35 wt.-% (Example 5)

[0120] f) Zirconium dioxide stabilised with 3 mol-% Y.sub.2O.sub.3; 40 wt.-% (Example 6)

[0121] g) Zirconium dioxide stabilised with 3 mol-% Y.sub.2O.sub.3; 45 wt.-% (Example 7)

[0122] h) Zirconium dioxide stabilised with 3 mol-% Y.sub.2O.sub.3; 5 wt.-% (Example 8)

[0123] Particle sizes: a) approx. 0.7 m, d.sub.90=1.3 m, d.sub.99<1.9 m

[0124] b) to f) d.sub.50 less than or equal to 500 nm, d.sub.90 less than or equal to 1.0 m

[0125] g) d.sub.50=560 nm, d.sub.90 less than or equal to 1.0 m

[0126] Viscosity of samples a) to g) from 40 to 15 mPas

[0127] (ii) liquid component:

[0128] Water: 20 to 55 wt.-%

[0129] Ethanol 10 to 30 wt.-%

[0130] Ethylene glycol: 5 to 40 wt.-%

[0131] (iii) Excipient dispersing agent/liquefying agent: 0.2 wt.-% Dolapix CE 64.

Examples 9 and 10Ink

[0132]

TABLE-US-00001 TABLE 1a Composition Ink In wt.-% Ex. 9 (A3) Ex. 10 Ex. 8 Ex. 6a Ex. 6b Ex. 11 Ethanol 24.0 14.0 35.0 13.0 4.5 62.3 Ethylene glycol 31.8 7.8 25.0 Glycerol; 9.0 22.0 Water (dist.) 24.0 49.0 34.5 24.5 42 Filling agent 20.0 (SiO.sub.2 29.0 5 (h, 40 (ZrO.sub.2, 3 40 wt.-% 37.5 raw material, (Aerosil ZrO.sub.2, 3 mol-% (ZrO.sub.2, 3 (ZrO.sub.2, 3 see Table 2, Ox50) mol-% Y.sub.2O.sub.3) mol-% mol-% 4, A3) Y.sub.2O.sub.3) Y.sub.2O.sub.3), Y.sub.2O.sub.3) Dispersing agent 0.2 Dolapix 0.2 0.5 3.48 0.4 Dolapix 0.2 CE 64 CE64 9.0 Byketol-PC Viscosity 19.28 mPa .Math. s 13.4 mPa .Math. s 3.48 mPa .Math. s 3.25 mPa .Math. s Surface tension 35.1 mN/m 55.1 mN/m 48.3 47.7

TABLE-US-00002 TABLE 1b Compositions Ink Example 13, In wt.-% Example 12 A3 Example 14 (A4) Ethanol 35.0 94.5 24.0 Ethylene 31.8 glycol Water (dist.) 24.0 Filling agent 60 (ZrO.sub.2, 3 mol-% 5.0 (SiO.sub.2 raw 20.0 (SiO.sub.2 raw Y.sub.2O.sub.3).sup.1 material, A3) material, see Table 2, 4, A4) Dispersing 5.0 0.5 0.2 Dolapix CE 64 agent Viscosity 6.48 13.4 Surface 35.1 55.1 tension .sup.1Particle size distribution as in examples 1 to 8

[0133] The ink and the droplets showed sufficient stability during the printing process (FIG. 1a and b; droplet settings: Voltage/pulse length 58/28, frequency 500 Hz after approx. 5 min., droplet size approx. 48 m). Dental ceramic filling agent in the ink (powdered component): d.sub.50=4.6 m, d.sub.100=17 m

TABLE-US-00003 TABLE 2 Filling agent in wt.-% in dental ink and powder bed - (composition material SiO.sub.2 raw material: A3, A2, A1) SiO.sub.2 70.45%, Al.sub.2O.sub.3 11.80%, K.sub.2O 8.50 5, Na.sub.2O 5.0%, Li.sub.2O 1.5%, CaO 1.0 5, B.sub.2O.sub.3 0.30%, F 0.6%, CeO.sub.2 0.85%

[0134] Powder bed (Table 3): flowable dental ceramic powder zirconium dioxide stabilised with 3 mol-% Y.sub.2O.sub.3

TABLE-US-00004 TABLE 3 Powder bed samples 1 and 2 dental ceramic powder - zirconium dioxide Samples 1 2 - silanised Composition ZrO.sub.2, 3 mol-% Y.sub.2O.sub.3 ZrO.sub.2, 3 mol-% Y.sub.2O.sub.3 d.sub.50 0.7 m 0.7 m Bulk density: [g/cm.sup.3] 3.61 3.33 Angle of repose [] 35.3 34.3 Theoretical density: 6.02 [g/cm.sup.3] Packing density [%] 60 55

[0135] Powder bed (Table 4): flowable dental powder SiO.sub.2 raw materialraw material Table 2

TABLE-US-00005 TABLE 4 Powder bed samples A1, A2, A3, and A4 Powder A1 (SiO.sub.2 raw material, Table 2) A2 A3 A4 A3 Composition +7% PVA Spray drying d.sub.10 <0.3 m <1.83 m <0.2 m d.sub.50 <5.0 <0.5 m <0.7 m <0.56 m <0.6 m d.sub.90 <10.8 <1.0 m <1.3 m <1.03 m <1.7 m d.sub.99 <2.0 m <1.84 m BET [m.sup.2/g] 1.28 Bulk density 0.42 [g/cm.sub.3] Angle of repose 52 []

[0136] Samples printed with a 3D printer. Microdrop MD-K-140-020 100 m, <20 mPas,

[0137] Printer: Servo drive: x/y: max: 600 mm/s, z max: 0.1 m, axial resolution: 0.1 m, positioning accuracy +/3 m.

[0138] Lifting floor: process speed: max. 50 mm/s, internal axial resolution: 0.1 m, positioning accuracy: +/5 m,

[0139] Installation space: 505050 mm

[0140] Printing resolution: 25 m

[0141] Droplet size: 50-60 m

[0142] Positioning accuracy: +/3 m

[0143] Bulk cup: Travel rate: max. 200 mm/s

[0144] Vibration frequency: max. 300 Hz

[0145] Layer thickness: 25 m

[0146] Example 1 Ceramics: The line distance, the droplet distance and the interference between lines are being defined. Powder bed: Sample A1, ink, example 9 (A3)

[0147] Cylindrical form bodies are being printed. Drying time Production Green body: 110 C., 24 h. Binding agent removal: t/T curve: Heating 50K/h to 500 C., hold time 30 minutes, Cooling: 100 K/h to room temperature

[0148] Sintering: a) Heating: 30 K/h to 869 C., hold time 1 minute (from 300 C. in vacuum), Cooling: within 15 minutes

[0149] Transparent dense form bodies of the above-mentioned samples were obtained. b) Powder bed A (Table 4) and ink example 9 (A3) were printed to form a form body and the binding agent was removed at 550 C. (and the sintering process took place at 850 C., 50 K/h). Transparent samples according to FIG. 1d were obtained. FIG. 1c shows the form body before the sintering process.

[0150] The addition of inorganic pigments, such as zirconium-praseodymium silicate (Zr,Pr)SiO4. CAS no.: 68187-15-5, zirconium-iron silicate (Zr, Fe(SiO4), (CAS no: 68412-79-3) with d.sub.50<5 m and the use of a printing head with four ink containers allowed coloured translucent form bodies to be produced.

[0151] Using the ink according to example 9 and adding pigments, a form body of a crown was printed (shrinkage calculated) and sintered. A crown with translucent properties was obtained after the sintering process.

[0152] Example 2: Powder bed: Sample A3+PVA (Table 4), ink example 9. The procedure was analogous to example 1. Translucent and transparent form bodies were obtained. No inclusions of air were observed.

[0153] Example 3: Powder bed: Sample A1, ink, example 10 The procedure was analogous to example 1.

[0154] Example 4: Powder bed: Sample A3+PVA, ink example 10. The procedure was analogous to example 1.

[0155] Example 5: An ink with added pigment and solid (example 9 (A3), 0.5 wt.-% pigment 3240 yellow) and powder bed sample A3+PVA analogous to example 1 was printed and sintered.

[0156] Example 6: An ink with added pigment and solid (example 9 (A3), 0.5 wt.-% pigment 3240 yellow) and powder bed sample A2 analogous to example 1 was printed and sintered.

[0157] Example 7: An ink with added pigment and solid (example 9 (A3), 0.5 wt.-% pigment PS 3210 (pink)) and powder bed sample A3+PVA analogous to example 1 was printed and sintered.

[0158] Example 8: Powder bed: Sample A3+PVA, ink example 13. The procedure was analogous to example 1. Translucent and transparent form bodies were obtained. No inclusions of air were observed.

[0159] Example 9: Powder bed: Sample A3+PVA, ink example 14. The procedure was analogous to example 1. Translucent and transparent form bodies were obtained. No inclusions of air were observed.

[0160] Example 10 Ceramics: Powder bed: Table 3 Sample 1, ink example 8 The procedure was analogous to example 1. Translucent and transparent form bodies were obtained. No inclusions of air were observed.

[0161] Example 11 Ceramics: Powder bed: Table 3 Sample 1, ink example 6b. The procedure was analogous to example 1. Translucent and transparent form bodies were obtained. No inclusions of air were observed.

[0162] Example 12 Ceramics: Powder bed: Table 3 Sample 1, ink example 12 The procedure was analogous to example 1. Translucent and transparent form bodies were obtained. No inclusions of air were observed.

[0163] Example 13 Ceramics: Powder bed: Table 3 Sample 2, ink example 8 The procedure was analogous to example 1. Translucent and transparent form bodies were obtained. No inclusions of air were observed.

[0164] Example 14 Ceramics: Powder bed: Table 4 Sample A3, ink example 9 (A3). The procedure was analogous to example 1. Translucent and transparent form bodies were obtained. No inclusions of air were observed.

[0165] Example 15 Ceramics: Powder bed: Table 3 Sample 1 at a weight ratio of 1 : 1 to sample 1* with d.sub.99 being less than or equal to 500 nm, ink example 3. The procedure was analogous to example 1. Translucent and transparent form bodies were obtained. No inclusions of air were observed.

[0166] Example 16 Ceramics: Powder bed: Table 3 Sample 1 at a weight ratio of 1 : 1 to sample 1* with d.sub.99 being less than or equal to 150 nm, ink example 5. The procedure was analogous to example 1. Translucent and transparent form bodies were obtained. No inclusions of air were observed (more than 15% [rel. translucency]).