Auto-polymerizable prosthetic material and polymerized, fracture-tough prosthetic material with increased colour stability

Abstract

The subject matter of the invention is an autopolymerisable two-component prosthetic base material and a method for its production comprising A) at least one liquid monomer component, and B) at least one powdered component, whereby the prosthetic material comprises in components (A) and/or (B) (i) at least one initiator or one initiator system for autopolymerisation, (ii) core-shell particles modified by an elastic phase, and (iii) at least one urethane (meth)acrylate.

Claims

1. Autopolymerisable two-component prosthetic base material comprising a mixture of the following components (A) and (B): (A) at least one liquid monomer component, (B) at least one powdered component, wherein the at least one liquid monomer component (A) comprises: (i) at least one initiator or one initiator system for autopolymerisation, (ii) core-shell particles modified by an elastic phase, (iii) at least one urethane dimethacrylate; and (iv) at least one polymerizable monomer; wherein (ii) core-shell particles modified by at least one elastic phase are present at 0.001 to 5% by weight, based on a total weight of component (A).

2. Prosthetic base material according to claim 1, wherein the distribution of the elastic phase of the modified core-shell particles is selected from possibilities a to d: a) elastic phase as core in solid outer shell (core-shell-particles); b) multiple elastic phases as cores in a solid matrix; c) core-shell particles from a) distributed in solid matrix, and d) solid core with elastic phase as outer shell.

3. Prosthetic base material according to claim 1, wherein the at least one powdered component (B) comprises: a) polymeric particles comprising polymers in the form of polymer powder comprising polyalkyl(meth)acrylates, optionally being crosslinked and being present as homopolymer or copolymer, whereby the polymers are based on at least one monomer comprising a (meth)acrylate group, selected from methylmethacrylate, ethylmethacrylate, propylmethacrylate, butylmethacrylate, n-hexylmethacrylate, 2-phenoxyethylmethacrylate, isobornylmethacrylate, isodecylmethacrylate, polypropylene glycol monomethacrylate, tetrahydrofurylmethacrylate, methylacrylate, ethylacrylate, propylacrylate, butylacrylate, n-hexylacrylate, 2-phenoxyethylacrylate, isobornylacrylate, isodecylacrylate, polypropylene glycol monoacrylate, tetrahydrofurylacrylate, hydroxyethylacrylate, hydroxypropylacrylate, hydroxyethyl methacrylate, hydroxypropylmethacrylate, a mixture comprising at least one of said (meth)acrylates and/or copolymers comprising one or at least two of the afore-mentioned monomers, polyamide particles, polyamide fibers, and optionally b) inorganic fillers comprising pyrogenic or precipitated silicas, dental glasses, zeolites, amorphous spherical fillers based on oxide or mixed oxide, glass fibres and/or carbon fibers, as well as mixtures comprising said powdered components a) and b).

4. Prosthetic base material according to claim 1, wherein the at least one powdered component (B) comprises polymethylmethacrylate (PMMA) beads as polymeric particles and/or splitter polymers, copolymers, comprising as comonomers, being polymerised into the copolymer, styrene, alpha-methylstyrene, vinyltoluene, substituted vinyltoluene, vinylhalogenide, vinylester, heterocyclic vinyl compounds, cyclopentene, (meth)acrylic acid ester, further acrylonitrile, maleic acid and maleic acid derivatives, fumaric acid and fumaric acid derivatives, acrylic acid, methacrylic acid, acryl(meth)acrylates, as well as, optionally, mixtures of said comonomers.

5. Prosthetic base material according to claim 1, wherein the elastic phase is selected from poly-(n-butyl acrylates) (PBA), butadiene-styrene copolymers, nitrile-butadiene copolymers, silicon rubber (graft copolymers), polyurethane polymers, polyolefin-based polyurethanes (polybutadiene-based polyurethanes), polydimethylsiloxane-modified polyurethanes, epoxy-functionalised elastic phases.

6. Prosthetic base material according to claim 1, wherein the solid shell, the solid core and/or the solid matrix are selected from (meth)acrylate polymers, polystyrene, epoxy-functionalised shell, metal oxide particles less than 100 nm as core, as well as homo-condensates or co-condensates of the afore-mentioned polymers.

7. Prosthetic base material according to claim 1, wherein the at least one liquid monomer component (A) comprises at least one monomer or a mixture of monomers selected from: a) methylmethacrylate, ethylmethacrylate, propylmethacrylate, butylmethacrylate, n-hexylmethacrylate, 2-phenoxyethylmethacrylate, isobornylmethacrylate, isodecylmethacrylate, polypropylene glycol monomethacrylate, tetrahydrofurylmethacrylate, methylacrylate, ethylacrylate, propylacrylate, butylacrylate, n-hexylacrylate, 2-phenoxyethylacrylate, isobornylacrylate, isodecylacrylate, polypropylene glycol monoacrylate, tetrahydrofurylacrylate, hydroxyethylacrylate, hydroxypropylacrylate, hydroxyethylmethacrylate, hydroxypropylmethacrylate, benzyl-, furfuryl- or phenyl(meth)acrylate, a mixture comprising at least one of said (meth)acrylates and/or copolymers comprising one or at least two of the afore-mentioned monomers, and/or b) two- and/or multi-crosslinking agents comprising 1,4-butandiol dimethacrylate (1,4-BDMA) or pentaerythritol tetraacrylate, bis-GMA monomer (bisphenol-A-glycidylmethacrylate, triethylene glycol dimethacrylate (TEGDMA) and diethylene glycol dimethacrylate (DEGMA), tetraethylene glycol di(meth)acrylate, decanediol di(meth)acrylate, dodecandiol di(meth)acrylate, hexyldexandiol 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, a mixture comprising at least one of said (meth)acrylates and/or copolymers comprising one or at least two of the afore-mentioned monomers.

8. Prosthetic base material according to claim 1, wherein at least some of the core-shell particles are present as aggregates of primary particles and the primary particles of the core-shell particles have diameters from 500 nm to 10 nm.

9. Prosthetic base material according to claim 1, which additionally comprises one or more substances from the group consisting of fillers, pigments, stabilizers, regulators, antimicrobial additives, UV-absorbing agents, thixotroping agents, catalysts and crosslinkers.

10. Prosthetic base material according to claim 1, which additionally comprises at least one initiator or at least one initiator system for autopolymerisation, which are present in (A) and (B).

11. Prosthetic base material according to claim 1, wherein the at least one initiator or the at least one initiator system for autopolymerisation comprises a) at least one initiator, and optionally b) at least one activator, or c) at least one initiator system selected from redox system.

12. Prosthetic base material according to claim 1, comprising (ii) core-shell particles modified by at least one elastic phase of 0.001 to 10% by weight, based on the total composition of component (A), and (iii) at least one urethane dimethacrylate of 0.001 to 20% by weight, based on the total composition of component (A).

13. Method for producing a polymerized prosthetic base material, said comprising the following steps: (a) providing a prosthetic base material according to claim 1 and (b) polymerizing the prosthetic base material.

14. Method according to claim 13, wherein component (A) and component (B) are present in the prosthetic base material at a weight ratio of (A):(B) ranging from 1:50 to 50:1.

15. Method according to claim 13, which comprises before step (b) introducing the prosthetic base material into a negative form of at least one dental prosthetic molded body.

16. Polymerised prosthetic base material obtainable by a method according to claim 13.

17. Polymerised prosthetic base material according to claim 16, which has a fracture toughness of ≥1.9 Mpa.Math.m.sup.1/2 and a total fracture work of ≥900 J/m.sup.2.

18. Kit comprising an autopolymerisable prosthetic base material according to claim 1, whereby the kit comprises separated components (A) and (B).

19. An autopolymerisable two-component prosthetic base material comprising a mixture of the following components (A) and (B): (A) at least one liquid component, and (B) at least one powdered component, wherein the at least one liquid component (A) comprises: (i) at least one initiator or one initiator system for autopolymerisation, (ii) 0.001 to 5% by weight, based on a total weight of all liquid components, of formerly aggregated core-shell particles that have been degraded by suspending into core-shell primary particles, the core-shell primary particles being modified by an elastic phase, (iii) at least one urethane dimethacrylate, and (iv) at least one polymerizable monomer.

20. A method for producing a polymerised prosthetic base material, said method comprising polymerizing the autopolymerisable two-component prosthetic base material according to claim 19.

21. Polymerised prosthetic base material obtained by the method according to claim 20.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The subject matter of the invention is illustrated in more detail by FIGS. 1a to d, without meaning to thus limit the invention to these embodiments.

(2) FIG. 1a and FIG. 1b: SEM—images of the core-shell particles (left: 100×, right: 10,000×)

(3) FIGS. 1c and d: SEM-image of the additive being suspended in MMA and dried prior to the image (left: 500×, right: 10,000×)

EXAMPLES

(4) Producing the powder mixture (B) according to the invention: A mixture is produced from PMMA beads of different particle sizes (bead 1 homopolymer (d.sub.50˜40-50 μm) 60-70%, bead 2 (d.sub.50˜55-70 μm) 15%, bead 3 copolymer (d50˜40-50 μm) 15%) with the addition of barbituric acid and colour pigments.

(5) Producing the liquid/monomer mixture (A) according to the invention: A mixture is produced from methylmethacrylate, and another methacrylate-based multi-crosslinker with the addition of stabilizers and initiators (barbituric acid/copper-system). In addition, the urethane dimethacrylate according to the invention, as well as the core-shell particles according to the invention are being added.

(6) Example according to the invention powder mixture and liquid mixture:

(7) TABLE-US-00001 Comparative Comparative Comparative Ex. 1 without Ex. 2 without Ex. 3 with core-shell and core-shell and core-shell and without urethane with urethane without urethane Example 1 (meth)acrylate (meth)acrylate (meth)acrylate Liquid methylmethacrylate 93.3 98.3 95.3 96.3 2-(4,6-diphenyl-1,3,5- 0.3 0.3 0.3 0.3 triazine-2-yl)-5- ((hexyl)oxy)-phenol N-methyl-N,N- 0.2 0.2 0.2 0.2 dioctyloctane-1- ammoniumchloride solution of copper(II) 0.1 0.1 0.1 0.1 chloride N,N-Bis(2- 0.1 0.1 0.1 0.1 hydroxyethyl)-p- toluidine total 94.00 99.00 96.00 97.00 di-functional aliphatic 3.00 — 3.00 — urethane acrylate oligomer tris(2-hydroxyethyl)- 1.00 1.00 1.00 1.00 isocyanurate triacrylate core-shell particles 2.00 — — 2.00 total 100.00 100.00 100.00 100.00 Powder PMMA/PMA 67.5 67.5 67.5 67.5 d.sub.50~40-45 μm PMMA 15.000 15.000 15.000 15.000 d.sub.50~40-55 μm cross-linked PMMA 15.000 15.000 15.000 15.000 d.sub.50~55-70 μm phenylbenzylbarbituric 2.5 2.5 2.5 2.5 acid total 100.000 100.000 100.000 100.000

(8) TABLE-US-00002 TABLE 1 Comparison of the example according to the invention and the comparative examples Physical properties (Norm ISO 20795-1) Comparative Comparative Comparative Example 1 Ex. 1 Ex. 2 Ex. 3 flexural strength >60 69.7 69.1 67.8 70.5 [MPa] E-modulus [MPa] >1500 2365 2417 2374 2397 fracture toughness >1.9 2.45 1.77 1.77 2.39 [MPa m1/2] total fracture work >900 1041.18 325.61 340.37 856.67 [J/m.sup.2] transparency [delta −3.16 −7.04 −4.88 −3.36 %] (after 6 d/37° C. of storage in Ringer's solution)

(9) Production of test bodies, determination of colour values, determination of mechanical properties:

(10) Colour test bodies: The following powder mixtures and monomer mixtures at a ratio of 10 g powder to:7 ml liquid are vigorously mixed and test bodies with dimensions of 30×30×3 mm are poured after the swelling phase (approximately 5 min at 23° C.) and polymerised in Palamat elite for 30 min at 55° C. and 2 bar pressure.

(11) Test bodies for mechanical strength: The following powder mixtures and monomer mixtures at a ratio of 10 g powder:7 ml liquid are vigorously mixed and test bodies with dimensions of 100×100×5 mm are poured after the swelling phase (approximately 5 min at 23° C.) and polymerised in Palamat elite for 30 min at 55° C. and 2 bar pressure.

(12) Subsequently, the test plates are sawed to the geometry stated in ISO 20795-1 and are polished.

(13) Test bodies for mechanical tests are produced in steel moulds, test bodies for colorimetric tests are produced in duplicating gels.

(14) To determine the transparency, the test bodies are stored for 5 days in Ringer's solution at 37° C., and the colour values and transparency are determined both before and after storage using 3 mm-plates. The measurements of table 1 are made according to DIN EN ISO 20795-1.

(15) The monomer mixture according to the invention shows significantly improved fracture toughness over all comparative examples, increased transparency, as well as the least loss of transparency after storage in Ringer's solution (reduced tendency to whitening).