Monochromatic Dental Shaped Article And Blank For Making Dental Restorations

Abstract

Monochromatic dental shaped body, which has an opacity of from 70 to 78%, and a process for its production.

Claims

1. Monochromatic dental shaped body comprising a polymerized resin matrix and at least one filler comprising an organic filler, a composite filler, or a mixture thereof, wherein the monochromatic dental shaped body has an opacity of from 70 to 78%.

2. Shaped body according to claim 1, wherein the opacity is from 72 to 76%.

3. Shaped body according to claim 1, further comprising inorganic filler.

4. Shaped body according to claim 1, wherein the polymeric resin matrix is formed by polymerization of a monomer or a mixture of monomers which is/are selected from monofunctional monomers, polyfunctional monomers or a mixture of mono- and polyfunctional monomers.

5. Shaped body according to claim 4, wherein the monofunctional monomer(s) is/are selected from methyl methacrylate, ethyl methacrylate, 2-hydroxyethyl methacrylate, butyl methacrylate, benzyl methacrylate, tetrahydrofurfuryl methacrylate, isobornyl methacrylate, p-cumyl-phenoxyethylene glycol methacrylate (CMP-1E) and acetoxyacetylethyl methacrylate (AAEMA).

6. Shaped body according to claim 4, wherein the polyfunctional monomer(s) is/are selected from bisphenol A dimethacrylate, 2,2-bis[4-(2-hydroxy-3-methacryloyloxypropyl)phenyl]propane (bis-GMA; an addition product of methacrylic acid and bisphenol A diglycidyl ether), ethoxy- or propoxylated bisphenol A dimethacrylate, 2-[4-(2-methacryloyloxyethoxyethoxy)phenyl]-2-[4-(2-methacryloyloxyethoxy)phenyl]propane), 2,2-bis[4-(2-methacryloxypropoxy)phenyl]propane, 1,6-bis-[2-methacryloyloxyethoxycarbonylamino]-2,2,4-trimethylhexane (UDMA; an addition product of 2-hydroxyethyl methacrylate and 2,2,4-trimethylhexamethylene diisocyanate), TMX-UDMA (an addition product of a mixture of HEMA and hydroxypropyl methacrylate (HPMA) with , , ,-tetramethyl-m-xylylene diisocyanate (TMXDI)), di-, tri- or tetraethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetramethacrylate, glycerol di- or trimethacrylate, 1,4-butanediol dimethacrylate, 1,10-decanediol dimethacrylate (D.sub.3MA), 1,12-dodecanediol dimethacrylate and bis(3-methacryloyloxymethyl)tricyclo-[5.2.1.0.sup.2,6]decane (DCP).

7. Shaped body according to claim 4, wherein the polymeric resin matrix is formed by polymerization of a mixture of methyl methacrylate, at least one of UDMA and, and ethylene glycol dimethacrylate.

8. Shaped body according to claim 3, wherein the inorganic filler comprises pulverulent SiO.sub.2, ZrO.sub.2 and/or BaSO.sub.4.

9. Shaped body according to claim 1, wherein the at least one filler comprises which a filler which has a lower opacity than the resin matrix.

10. Shaped body according to claim 41, wherein the organic filler and/or the composite filler have a lower opacity than the resin matrix.

11. Shaped body according to claim 1 further comprising a thickener.

12. Shaped body according to claim 1, wherein the composite filler is obtainable by curing a composite pastes based on a dimethacrylate mixtures and at least one inorganic fillers, wherein the dimethacrylate mixtures comprises bis-GMA, (TMX-)UDMA and/or D.sub.3MA, and wherein the at least one inorganic filler is selected from radiopaque glass fillers and/or ytterbium trifluoride.

13. Shaped body according to claim 11, wherein the thickener has an average particle size of from 10 to 60 m and the at least one filler has an average particle size of from 2 to 60 m.

14. Shaped body having an opacity of from 70 to 78% for use as a blank for the production of dental restorations, which is obtained by curing the following mixture: (1) 1 to 20 wt.-% polyfunctional radically polymerizable monomer(s), (2) 10 to 60 wt.-% monofunctional radically polymerizable monomer(s), (3) 0.01 to 5.0 wt.-% initiator for the radical polymerization, (4) 20 to 70 wt.-% thickener, (5) 5 to 50 wt.-% organic filler and optionally (6) 0.1 to 5.0 wt.-% further additive(s), in each case relative to the total mass of the mixture.

15. Shaped body according to claim 14, which is obtained by curing the following mixture: (1) 2 to 10 wt.-% polyfunctional radically polymerizable monomer(s), (2) 5 to 50 wt.-% monofunctional radically polymerizable monomer(s), (3) 0.1 to 3.0 wt.-% initiator for the radical polymerization, (4) 30 to 60 wt.-% thickener, (5) 10 to 40 wt.-% organic filler and optionally (6) 0.1 to 2.0 wt.-% further additive(s), in each case relative to the total mass of the mixture.

16. Shaped body according to claim 14, which is obtained by curing the following mixture: (1) 3 to 8 wt.-% polyfunctional radically polymerizable monomer(s), (2) 10 to 45 wt.-% monofunctional radically polymerizable monomer(s), (3) 0.1 to 2.0 wt.-% initiator for the radical polymerization, (4) 35 to 55 wt.-% thickener, (5) 15 to 35 wt.-% organic filler and optionally (6) 0.2 to 1.5 wt.-% further additive(s), in each case relative to the total mass of the mixture.

17. Shaped body according to claim 11, wherein the thickener comprises uncrosslinked polymer particles as thickener.

18. Shaped body according to claim 1, wherein the organic filler comprises crosslinked polymer particles.

19. Shaped body according to claim 1, further comprising at least one pigment as colorant.

20. Shaped body according to claim 19, which comprises 0.0002 to 1.0 wt.-% pigment(s), relative to the total mass of the shaped body.

21. Process of using the shaped body according to claim 1 for the production of artificial teeth or tooth segments.

22. Process according to claim 21, wherein the artificial teeth or the tooth segments are produced by a cutting process.

23. Process according to claim 22, wherein the artificial teeth or the tooth segments are produced by a CAD/CAM process.

24. Process for the production of a shaped body according to claim 1, wherein (a) a polymerizable mixture is provided, which contains radically and/or cationically polymerizable resin, filler and initiator for the radical and/or cationic polymerization, (b) the mixture is coloured by the addition of colorants, (c) the opacity of the mixture is optionally adjusted by the addition of fine-grained filler and/or pigment(s), and (d) the mixture is shaped to form a shaped body and (e) cured by radical and/or cationic polymerization.

25. Process according to claim 24, wherein, in step (c), the opacity is adjusted by addition of TiO.sub.2, SiO.sub.2, ZrO.sub.2 and/or BaSO.sub.4.

26. Process according to claim 24, wherein the shaped body is shaped in step (d) by introducing the mixture into a casting mould by injection moulding followed by curing.

27. Process according to claim 24, wherein the shaped body is shaped in step (d) by an additive process and cured in layers.

Description

[0087] The invention is described in more detail below by means of figures and embodiment examples.

[0088] FIGURE 1 shows teeth milled from blanks according to the invention in comparison with plastic teeth customary in the trade of the same colour with a multilayer structure.

EMBODIMENT EXAMPLES

Example 1

[0089] Preparation of a Polymerizable Composition for the Production of Shaped Bodies

[0090] The components indicated in Table 1 were mixed with each other to form a homogeneous mixture. In order to achieve a as homogeneous as possible pigment distribution, the pigments were firstly mixed homogeneously with the uncrosslinked polymer particles (see Table 2) and this mixture was then mixed with the remaining components. Test pieces with a diameter of 20 mm and a height of 20.02 mm were polymerized from the mixture formed. The polymerization was effected in a pressure polymerizer (Ivomat IP3, Ivoclar Vivadent AG) at 120 C. under water at a pressure of 6 bar for 15 min. The obtained test pieces were wet-polished with a wet-grinding machine with sandpaper (P4000 grit) before the colour and opacity measurement. The opacity and colour measurements were effected with a Minolta CM-3700d colour-measuring instrument. This instrument uses a xenon flash (pulsed xenon arc lamp, wavelength 360 to 740 nm). The colour was measured corresponding to the L*a*b* colour model according to DIN EN ISO 11664-4. The results are shown in Table 3.

TABLE-US-00003 TABLE 1 Compositions for the production of shaped bodies Component Ex. 1a Ex. 1b Monomer methyl methacrylate (MMA) 80 g 80 g CAS 80-62-6 urethane dimethacrylate(UDMA) 12.5 g CAS 72869-86-4 TMX-UDMA 10 g CAS 1809948-82-0 ethylene glycol dimethacrylate 7.5 g 10 g CAS 97-90-5 Thickener PMMA powder (average grain 119 g 139 g size 40 to 60 m)* CAS (PMMA) 9011-14-7 Filler polymer powder 80 g (UDMA polymerized and ground to an average grain size of 20 m) polymer powder 60 g (TMX-UDMA polymerized and ground to an average grain size of 15 m) Initiator benzoyl peroxide 1 g 1 g CAS 94-36-0 *Mixture of uncrosslinked pearl polymer particles and pigments according to Table 2

TABLE-US-00004 TABLE 2 Composition of the mixture of PMMA powder and pigments Components Weight-% PMMA pearl polymer 99.8606 TiO.sub.2 white pigment 0.1200 Microlith Yellow types 0.0089 Sicovit Yellow 0.0032 Sicovit Black 0.0022 Microlith Red 0.0029 Lumilux fluorescent agent 0.0022 Total 100.0000

TABLE-US-00005 TABLE 3 Colour and opacity of Ex. 1a/b after 1st coloration L*a*b* values according to L*a*b* colour system B Colour*.sup.) L A yellow- A3 Lightness red-green blue Opacity Ex. 1a 77.51 9.03 29.71 73.95 Ex. 1b 77.40 8.72 30.16 73.90 *.sup.)Colour designation according to Vita Lumin-VACUUM shade guide

[0091] In Example 1, the desired opacity was achieved by the combination of PMMA powder (thickener) and organic filler (crosslinked polymer; splinter polymer). The shaped bodies are characterized by a natural translucence, light scattering and colour effect.

Example 2

[0092] Production of Tooth-Shaped Shaped Bodies

[0093] For production of tooth-shaped shaped bodies firstly cylindrical blanks with appropriate dimensions were produced and then prosthetic teeth were milled therefrom. The blanks were produced from materials based on the formulation from Example 1, which were coloured according to requirements. After adjustment of the base colour, the opacity was measured as described in Example 1 using test pieces. The remaining powder mixture was then adjusted to the opacity values named in Table 4 by the addition of further TiO.sub.2. The material was polymerized to form discs after the coloured powder mixtures with monomer had been made into a paste (mixing ratio see Table 1), in each case in a steel mould by means of a hydraulic hot press at 140 C. and a pressure of 30 bar for 20 min. Teeth with the external geometry of existing ready-made prosthetic teeth were milled from the thus-produced discs using a dental milling machine (Zenotec Select Ion, Wieland Dental). The teeth had a very natural appearance (FIG. 1) and can be used directly for the production of prostheses without veneering.

TABLE-US-00006 TABLE 4 Colour and opacity of tooth-shaped shaped bodies L*a*b* values according to L*a*b* colour system Colour*.sup.) L a b Opacity BL3 86.07 3.42 15.50 73.50 A1 83.80 5.02 22.33 72.69 A2 79.60 7.65 26.44 73.59 A3 78.44 8.33 29.04 72.99 A3.5 76.65 9.53 31.40 73.56 B1 82.51 3.83 21.43 73.88 B3 78.03 7.41 32.00 73.41 C2 75.62 6.26 25.43 75.55 D2 77.79 5.89 22.31 74.04 *.sup.)Colour designation according to Vita Lumin-VACUUM shade guide

Example 3

Comparison Example

[0094] Measurement of Conventional CAD Discs

[0095] The colour and the opacity of PMMA discs customary in the trade (PMMA-Telio CAD disc, Wieland Dental) were measured in the manner described in Example 1. The test pieces with a diameter of 20 mm and a height of 20.02 mm required for the measurement were milled from the blanks. The measured values are indicated in Table 5. In all colour shades the discs have a much higher opacity than blanks according to the invention. The discs are provided for the production of crowns. The opacity is high enough that the tooth stump is sufficiently covered, does not show through and does not have an adverse effect on the colour. According to Table 5, up to 81.49% of the incident luminous flux is blocked and a maximum of 21.47% of the incident light passes through the material. In the case of an opacity of 100%, the incident light would be completely blocked (0% passage); in the case of an opacity of 0%, 100% of the incident light would pass through the sample.

[0096] Artificial teeth which are produced from these discs differ from teeth made of materials according to the invention through a dull colour effect, which is reminiscent of the appearance of bone.

TABLE-US-00007 TABLE 5 Colour and opacity of customary PMMA discs.sup.1) L*a*b* values according to L*a*b* colour system Colour.sup.2) L a b Opacity BL3 86.29 2.24 15.07 81.49 A1 84.17 3.96 21.01 78.80 A2 81.64 6.44 25.25 78.53 A3 77.17 8.61 25.27 79.87 A3.5 75.37 11.29 29.69 78.96 B1 85.13 1.48 20.53 79.78 B3 75.09 9.40 29.17 80.56 C2 72.82 6.36 22.96 79.79 D2 75.22 6.50 20.16 79.13 .sup.1)(PMMA-Telio CAD for Zenotec, Wieland Dental) .sup.2)Colour designation according to Vita Lumin-VACUUM shade guide

Example 4

Comparison Example

[0097] Measurement of Conventional Plastic Teeth

[0098] The colour and the opacity of the incisal layer and of the dentine layer of ready-made plastic teeth (Zahnlinie SR Vivodent S DCL, Ivoclar Vivadent AG) were measured in the manner described in Example 1. The test pieces with a diameter of 20 mm and a height of 20.02 mm required for the measurement were produced from the corresponding unpolymerized mixtures. The measured values are indicated in Tables 6 and 7. The measured values show that the dentine layer has a much higher opacity and the incisal layer a much lower opacity than the materials according to the invention. Nevertheless it was possible with the materials according to the invention from Example 4 to produce artificial teeth the appearance of which virtually matches the teeth customary in the trade. For 6 colour shades, in each case three teeth, which were milled from blanks according to the invention, are depicted in FIG. 1 together with in each case three teeth customary in the trade of the same colour. The match is astounding.

TABLE-US-00008 TABLE 6 Colour and opacity of the incisal layer of plastic teeth.sup.1) customary in the trade L*a*b* values according to L*a*b* colour system Colour.sup.2) L a b Opacity BL3 89.99 2.03 12.58 55.71 A1 90.12 1.13 14.47 52.29 A2 89.44 1.94 16.90 54.20 A3 89.35 1.35 19.87 52.97 A3.5 87.97 2.57 25.37 53.90 B1 90.00 0.46 14.87 53.55 B3 89.40 0.75 20.36 53.04 C2 87.40 1.55 21.68 53.73 D2 87.35 2.87 17.62 54.17 .sup.1)Zahnlinie SR Vivodent S DCL, Ivoclar Vivadent AG .sup.2)Colour designation according to Vita Lumin-VACUUM shade guide

TABLE-US-00009 TABLE 7 Colour and opacity of the dentine layer of plastic teeth.sup.1) customary in the trade L*a*b* values according to L*a*b* colour system Colour.sup.2) L a b Opacity BL3 85.50 2.88 13.18 85.88 A1 82.24 4.25 20.45 83.21 A2 78.55 6.85 26.76 84.63 A3 75.81 7.29 27.34 84.62 A3.5 73.57 9.98 31.59 84.73 B1 82.36 2.34 20.05 84.12 B3 74.81 8.37 33.71 83.48 C2 70.82 6.02 24.89 85.80 D2 74.28 5.14 20.20 85.64 .sup.1)Zahnlinie SR Vivodent S DCL, Ivoclar Vivadent AG .sup.2)Colour designation according to Vita Lumin-VACUUM shade guide