Fluorescent glasses and glass ceramics with high content of cerium and tin

Abstract

To provide fluorescent glasses and glass ceramics with high content of cerium and tin.SOLUTION: The invention relates to glasses and glass ceramics with high content of cerium and tin. The glasses and glass ceramics contain the following components: 48.0 to 75.0 wt.% of SiO2; 8.0 to 20.5 wt.% of Li2O; 4.0 to 20.0 wt.% of cerium, calculated as CeO2; and 3.1 to 15.7 wt.% of tin, calculated as SnO. The glasses and glass ceramics are particularly suitable for the preparation of dental restorations with fluorescence properties largely corresponding to those of natural teeth.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to glasses and glass ceramics which have a high content of cerium and tin and are particularly suitable for the production of dental restorations whose fluorescence properties largely correspond to those of natural teeth. The present invention also relates to a process for the preparation of the glasses and glass ceramics according to the invention and to their use as mixed components and as dental materials, in particular for the preparation of dental restorations. [Background technology]

[0002] Due to their good mechanical and optical properties, glass ceramics are used in dentistry, in particular for the production of dental crowns and mini-bridges.

[0003] WO 2017 / 032745 A1 describes low-quartz glass-ceramics of lithium silicate for use in dentistry, which contain fluorescent and coloring agents, preferably selected from Bi2O3 and Bi2O5, as well as inorganic pigments and / or oxides of d and f elements, such as the oxides of Mn, Fe, Co, Pr, Nd, Tb, Er, Dy, Eu and Yb.

[0004] From EP 3 696 150 A1 it is known that glasses and glass ceramics containing 0.05 to 5.0% by weight of europium, calculated as Eu2O3, impart advantageous fluorescence properties to dental restorations made from these glasses and glass ceramics.

[0005] It is known from W. Buchalla, “Comparative Fluorescence Spectroscopy Shows Differences in Non-Cavitated Enamel Lesions,” Caries Res. 2005, 39, 150-156 that natural teeth exhibit bluish-white fluorescence under ultraviolet light having a wavelength in the range of 400-650 nm.

[0006] Rukmani et al, J. Am. Ceram. Soc. 2007, 90, 706-711, describe the effect of V and Mn colorants on the crystallization behavior and optical properties of Ce-doped lithium disilicate glass ceramics. To prepare the glass ceramics, a mixture of the starting materials SiO2, ZrO2, Li2CO3, K2CO3, MgCO3 and Al(PO3)3 with CeO2, V2O5 and MnO2 is prepared, the mixture is melted at 1500 °C in a platinum crucible, cooled and then subjected to several heat treatments in a tube furnace with air supply. EP 3 696 149 A1 describes glasses and glass ceramics containing cerium and tin that fluoresce when excited with light of a wavelength of 366 nm. However, when excited with light of a wavelength of 395 nm, the glasses and glass ceramics described do not show any fluorescence. It has been shown that glasses and glass ceramics known from the prior art have poor fluorescence properties and are unable to adequately mimic the fluorescence properties of natural tooth materials, especially under light with a wavelength of about 380-430 nm. In particular, there is a need for glasses and glass ceramics that also exhibit good fluorescence properties, especially in the long-wave UV range, for example 380-430 nm. Light of these wavelengths is often used as "black light" in entertainment venues such as nightclubs. Thus, dental restorations with poor fluorescence properties may be recognized as restorations or may appear to be gaps or defects under the influence of long-wave UV light. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Publication No. 2017 / 032745 [Patent Document 2] European Patent Application Publication No. 3 696 150 [Patent Document 3] European Patent Application Publication No. 3 696 149 [Non-patent literature]

[0008] [Non-Patent Document 1] W. Buchalla, “Comparative Fluorescence Spectroscopy Shows Differences in Non-Cavitated Enamel Lesions,” Caries Res.2005,39,150-156 [Non-Patent Document 2] Rukmani et al,J.Am.Ceram.Soc.2007,90,706-711 Summary of the Invention [Means for solving the problem]

[0009] The present invention is based on the problem of providing glasses and glass ceramics that exhibit a fluorescence comparable to that of natural tooth materials and are therefore particularly suitable for the preparation of dental restorations that not only exhibit good mechanical properties but are also able to largely mimic the fluorescence properties of natural tooth materials when excited in the long-wavelength UV range, e.g. 380-430 nm. These glasses and glass ceramics should also be suitable as mixing components for adjusting the fluorescence properties of other glasses and glass ceramics.

[0010] This problem is solved according to the invention by the cerium- and tin-containing glasses and glass ceramics according to claims 1 to 11 and the use of these glasses and glass ceramics according to claims 14 and 15. The invention also relates to processes for preparing the inventive glasses and glass ceramics according to claims 12 and 13 and to a process for preparing dental restorations according to claim 16.

[0011] The present invention provides, for example, the following items. (Item 1) Cerium and tin containing glasses and glass ceramics having the following components: Ingredients Weight% SiO248.0~75.0 Li2O 8.0~20.5 Cerium calculated as CeO2 4.0~20.0 Tin calculated as SnO 3.1-15.7 Glasses and glass-ceramics comprising: (Item 2) %. The glasses and glass ceramics according to any one of the preceding items, which contain 50.0 to 72.0 wt.-%, in particular 52.0 to 70.1 wt.-%, and particularly preferably 57.0 to 70.1 wt.-% of SiO2. (Item 3) %. The glasses and glass ceramics according to any one of the preceding paragraphs, which contain 9.0 to 19.0 wt.-%, in particular 10.1 to 18.2 wt.-%, and particularly preferably 10.9 to 17.3 wt.-% LiO. (Item 4) %. The glasses and glass-ceramics according to any one of the preceding paragraphs, containing 4.3 to 19.0 wt.-%, preferably 4.7 to 18.5 wt.-%, in particular 5.3 to 17.9 wt.-%, more preferably 5.8 to 16.6 wt.-%, and particularly preferably 6.1 to 16.0 wt.-% of cerium, calculated as CeO2. (Item 5) %. The glasses and glass-ceramics according to any one of the preceding paragraphs, containing 3.4 to 14.9 wt.-%, preferably 3.7 to 14.5 wt.-%, in particular 4.1 to 14.0 wt.-%, more preferably 4.6 to 13.0 wt.-%, and particularly preferably 4.7 to 12.6 wt.-% tin, calculated as SnO. (Item 6) 10. The glass and glass-ceramic according to claim 9, wherein the molar ratio of cerium, calculated as CeO2, to tin, calculated as SnO, is in the range of 1.5:1 to 1:1.5, preferably 1.2:1 to 1:1.2, and in particular 1.1:1 to 1:1.1, and particularly preferably 1.0:1.0. (Item 7) The following ingredients in the amounts indicated: Ingredients Weight% SiO248.0~75.0 Li2O 8.0~20.5 Cerium calculated as CeO2 4.0~20.0 Tin calculated as SnO 3.1-15.7 Me I 2O 0~11.5 Me II O 0~11.0 Me III 2O30~8.0 Me IV O20~2.0 Me V 2O50~8.0 Terbium calculated as Tb4O7 0~3.5 Fluorine 0~5.0 wherein the compound contains at least one, and preferably all, of Me I 2O is in particular selected from Na2O, K2O, Rb2O and / or CsO2, Me II O is in particular selected from MgO, CaO, SrO, BaO and / or ZnO, Me III 2O3 is in particular selected from B2O3, Y2O3, La2O3, Ga2O3 and / or In2O3, Me IV O2 is in particular selected from ZrO2, TiO2 and / or GeO2, Me V 2O5 is in particular selected from P2O5, V2O5, Ta2O5 and / or Nb2O5; 4. The glass and glass ceramic according to any one of the preceding items. (Item 8) The following ingredients in the amounts indicated: Ingredients Weight% SiO248.0~75.0 Li2O 8.0~20.5 Cerium calculated as CeO2 4.0~20.0 Tin calculated as SnO 3.1-15.7 K2O 0~11.0 Al2O30~8.0 MgO 0~2.0 CaO 0~2.5 SrO 0~4.0 ZnO 0~2.2 Terbium calculated as Tb4O7 0~3.5 P2O50~8.0 ZrO20~2.0 The glass and glass ceramic according to any one of the preceding items, comprising at least one, and preferably all, of: (Item 9) 2. The glass of any one of the preceding claims, containing nuclei for crystallization. (Item 10) Glasses and glass ceramics comprising the cerium- and tin-containing glass or glass ceramic according to any one of the preceding items in an amount of preferably 0.1 to 60% by weight, in particular 1 to 58% by weight, preferably 5 to 56% by weight, particularly preferably 10 to 54% by weight, and more preferably 15 to 52% by weight. (Item 11) 8. The glasses and glass ceramics according to any one of the preceding items, wherein the glasses and glass ceramics are in the form of a powder, granules, a paste, an aerosol, a blank, a dental restoration, or a coating on a dental restoration. (Item 12) 2. A process for preparing the glasses and glass ceramics according to claim 1, wherein the tin is used at least in part in divalent form, in particular as SnO. (Item 13) 2. The process according to claim 1, wherein the starting materials of the glass or the components of the glass ceramic are melted at a temperature of 1400° C. to 1800° C., in particular 1450 to 1600° C., and particularly preferably about 1500° C., for a period of preferably 20 minutes to 10 hours. (Item 14) 4. Use of the glass or glass ceramic according to any one of the preceding items as a mixture component for adjusting the fluorescence of the glass or glass ceramic. (Item 15) 2. Use of a glass or glass ceramic according to any one of the preceding items as a dental material, in particular for preparing or coating a dental restoration. (Item 16) 1. A process for preparing a dental restoration, in particular an inlay, onlay, crown, partial crown, bridge, veneer, occlusal facet or abutment, in which a glass or glass ceramic according to any one of the previous items is given the shape of the desired dental restoration by pressing, sintering or machining, in particular as part of a CAD / CAM process. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 shows the advantageous fluorescence of the glass frit according to the invention. [Diagram 2] FIG. 2 shows the advantageous fluorescence of a glass-ceramic blank according to the invention. [Diagram 3] FIG. 3 shows the advantageous fluorescence of a glass-ceramic blank according to the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Description of the embodiments The present invention relates to a method for producing a composition comprising the following components: Ingredients Weight% SiO248.0~75.0 Li2O 8.0~20.5 Cerium calculated as CeO2 4.0~20.0 Tin calculated as SnO 3.1-15.7 and relates to glasses and glass ceramics with a high content of cerium and tin which are particularly suitable for the preparation of dental restorations having fluorescence properties which correspond largely to the fluorescence properties of natural teeth.

[0014] The present invention comprises the following components: Ingredients Weight% SiO248.0~75.0 Li2O 8.0~20.5 Cerium calculated as CeO2 4.0~20.0 Tin calculated as SnO 3.1-15.7 The present invention relates to glasses and glass ceramics containing cerium and tin, characterized in that they contain

[0015] Surprisingly, it has been shown that the glasses and glass ceramics according to the invention exhibit improved fluorescence properties compared to the prior art, especially when exposed to UV light having a wavelength of 380-430 nm, for example 395 nm. In the context of the present invention, it has been found that the use of higher levels of cerium and tin than known in the prior art causes a change in the fluorescence properties of the glasses and glass ceramics. In particular, it has been shown that by using higher percentages of cerium and tin, a clearly visible fluorescence can be obtained even at excitation wavelengths in the range of 380-430 nm. It has therefore been shown that the glasses and glass ceramics according to the invention are particularly suitable for imitating natural tooth materials.

[0016] Without being limited to any particular theory, it is believed that the use of higher amounts of cerium and tin results in a higher yield of Ce 3+ It is hypothesized that this changes the fluorescence properties of the ions and shifts the excitation spectrum, so that visible fluorescence can also be perceived in glasses and glass-ceramics when excited with light of a wavelength in the range of 380-430 nm, e.g. 395 nm.

[0017] According to the invention, the glasses and glass ceramics preferably contain 50.0 to 72.0% by weight, in particular 52.0 to 70.1% by weight and particularly preferably 57.0 to 70.1% by weight of SiO2.

[0018] The glasses and glass ceramics further preferably contain 9.0 to 19.0% by weight, in particular 10.1 to 18.2% by weight and particularly preferably 10.9 to 17.3% by weight of Li2O.

[0019] Preferably, the glasses and glass ceramics contain 4.3 to 19.0% by weight, in particular 4.7 to 18.5% by weight, more preferably 5.3 to 17.9% by weight, particularly preferably 5.8 to 16.6% by weight and most preferably 6.1 to 16.0% by weight of cerium, calculated as CeO2.

[0020] Further preferably, the glasses and glass ceramics contain 3.4 to 14.9% by weight, in particular 3.7 to 14.5% by weight, more preferably 4.1 to 14.0% by weight, particularly preferably 4.6 to 13.0% by weight and even more preferably 4.7 to 12.6% by weight of tin, calculated as SnO.

[0021] It is also preferred that the molar ratio of cerium, calculated as CeO2, to tin, calculated as SnO, is in the range of from 1.5:1 to 1:1.5, in particular from 1.2:1 to 1:1.2, and more preferably from 1.1:1 to 1:1.1, and particularly preferably 1.0:1.0.

[0022] In another preferred embodiment, the glasses and glass ceramics are Ingredients Weight% SiO250.0~72.0wt%, Li2O 9.0~19.0% by weight, 4.3-19.0% by weight of cerium, calculated as CeO2, and 3.4 to 14.9% by weight tin calculated as SnO; And especially: SiO252.0~70.1wt%, Li2O 10.1~18.2wt%, 4.7-18.5% by weight of cerium, calculated as CeO2, and 3.7 to 14.5% by weight tin calculated as SnO; And particularly preferably, SiO252.0~70.1wt%, Li2O 10.1~18.2wt%, 5.3-17.9% by weight of cerium, calculated as CeO2, and Tin calculated as SnO 4.1-14.0% by weight Contains:

[0023] In a particular embodiment, the glasses and glass ceramics further contain terbium. Preferably, the glasses and glass ceramics contain 0 to 3.5% by weight, in particular 0 to 2.6% by weight and particularly preferably 0.1 to 2.6% by weight of terbium, calculated as Tb4O7.

[0024] Glasses and glass ceramics may be prepared by adding further alkali metal oxides Me I It is also preferred that the alkali metal oxide Me I "2O" means an alkali metal oxide other than Li2O, and this Me I 2O is in particular selected from Na2O, K2O, Rb2O and / or Cs2O, and preferably selected from Na2O and / or K2O.

[0025] Further preferably, the glasses and glass ceramics contain 0 to 11.0% by weight, in particular 0 to 9.3% by weight, more preferably 1.0 to 8.0% by weight and particularly preferably 2.5 to 5.0% by weight of K2O.

[0026] Furthermore, the glasses and glass ceramics contain from 0 to 11.0% by weight, in particular from 1.0 to 10.0% by weight and particularly preferably from 2.0 to 8.0% by weight of oxides of further divalent elements Me II It is preferred that the term "further divalent element oxide Me II "MeO" means a divalent oxide other than SnO. II O is in particular selected from MgO, CaO, SrO, BaO and / or ZnO. Particularly preferably, the glasses and glass ceramics contain the following oxides of divalent elements MeO in the indicated amounts: II O: Ingredients Weight% MgO 0~2.0 CaO 0~2.5 SrO 0~4.0 ZnO 0~2.2 It contains at least one, particularly all, of:

[0027] Furthermore, the glasses and glass ceramics preferably contain 0 to 3.0 wt. %, and in particular 0 to 1.0 wt. %, BaO, and particularly preferably are substantially free of BaO.

[0028] It is also preferred that the glasses and glass ceramics contain 0 to 2.0% by weight, in particular 0 to 1.5% by weight, more preferably 0 to 1.0% by weight and particularly preferably 0.1 to 1.0% by weight of MgO.

[0029] In another preferred embodiment, the glasses and glass ceramics contain 0 to 2.5% by weight, in particular 0 to 1.8% by weight, more preferably 0 to 1.4% by weight and particularly preferably 0.1 to 1.4% by weight of CaO.

[0030] Furthermore, the glasses and glass ceramics preferably contain 0 to 3.0% by weight, more preferably 0 to 2.8% by weight, especially 0 to 2.5% by weight, and particularly preferably 0.1 to 2.5% by weight of SrO.

[0031] In a preferred embodiment, the glasses and glass ceramics contain 0 to 2.2% by weight, in particular 0 to 1.7% by weight, more preferably 0 to 1.3% by weight and particularly preferably 0.1 to 1.3% by weight of ZnO.

[0032] 0 to 8.0% by weight, in particular 0 to 7.0% by weight and particularly preferably 2.0 to 6.8% by weight of further oxides of trivalent elements Me III Glasses and glass ceramics containing 2O3 are further preferred. The term "oxides of further trivalent elements Me III "2O3" means a trivalent oxide other than Ce2O3, where Me III2O3 is in particular selected from Al2O3, B2O3, Y2O3, La2O3, Dy2O3, Ga2O3 and / or In2O3, and preferably selected from Al2O3, B2O3, Y2O3 and / or La2O3.

[0033] In a preferred embodiment, the glasses and glass ceramics further contain 0 to 8.0 wt. %, more preferably 0 to 6.8 wt. %, even more preferably 1.0 to 6.0 wt. %, and particularly preferably 2.0 to 4.0 wt. % Al2O3.

[0034] In addition, the glasses and glass ceramics contain oxides of further tetravalent elements Me IV O2 in an amount of 0 to 2.0% by weight, preferably 0 to 1.5% by weight, in particular 0 to 1.0% by weight, and preferably 0.1 to 1.0% by weight. IV "O2" means tetravalent oxides other than SiO2, CeO2 and SnO2, and this Me IV O2 is in particular selected from ZrO2, TiO2 and / or GeO2.

[0035] It is also preferred that the glasses and glass ceramics contain 0 to 2.0% by weight, in particular 0 to 1.5% by weight, more preferably 0 to 1.0% by weight and particularly preferably 0.1 to 1.0% by weight of ZrO2.

[0036] In a preferred embodiment, the glasses and glass ceramics are made of oxides of pentavalent elements Me V 2O5 in an amount of 0 to 8.0% by weight, particularly 0 to 7.0% by weight, preferably 1.0 to 7.0% by weight, more preferably 2.0 to 6.8% by weight, and particularly preferably 3.0 to 6.5% by weight. V 2O5 is in particular selected from P2O5, V2O5, Ta2O5 and / or Nb2O5, and particularly preferably selected from P2O5 and / or Ta2O5. In this context, P2O5 may in particular act as a nucleating agent. However, the presence of a nucleating agent is not absolutely necessary according to the invention.

[0037] Furthermore, the glasses and glass ceramics preferably contain 0 to 8.0% by weight, in particular 0 to 7.0% by weight, more preferably 0 to 6.8% by weight and particularly preferably 1.0 to 6.5% by weight of P2O5.

[0038] Furthermore, the glasses and glass ceramics may contain 0 to 5.0 wt. % and in particular 0 to 2.0 wt. % fluorine.

[0039] The following ingredients in the amounts indicated: Ingredients Weight% SiO248.0~75.0 Li2O 8.0~20.5 Cerium calculated as CeO2 4.0~20.0 Tin calculated as SnO 3.1-15.7 Me I 2O 0~11.5 Me II O 0~11.0 Me III 2O30~8.0 Me IV 2O 0~2.0 Me V 2O50~8.0 Terbium calculated as Tb4O7 0~3.5 Fluorine 0~5.0 Particularly preferred are glasses and glass ceramics which contain at least one, preferably all, of Me I 2O, Me II O, Me III 2O3, Me IV 2O and Me V 2O5 in particular has the meaning given above.

[0040] In another preferred embodiment, the glasses and glass ceramics contain the following components in the indicated amounts: Ingredients Weight% SiO248.0~75.0 Li2O 8.0~20.5 Cerium calculated as CeO2 4.0~20.0 Tin calculated as SnO 3.1-15.7 K2O 0~11.0 Al2O30~8.0 MgO 0~2.0 CaO 0~2.5 SrO 0~4.0 ZnO 0~2.2 Terbium calculated as Tb4O7 0~3.5 P2O50~8.0 ZrO20~2.0 It contains at least one, preferably all, of:

[0041] In another particularly preferred embodiment, the glasses and glass ceramics contain the following components in the indicated amounts: Ingredients Weight% SiO252.0~70.1 Li2O 10.1~18.2 Cerium calculated as CeO2 4.3~19.0 Tin calculated as SnO 3.4-14.9 K2O 0~9.3 Al2O30~6.8 MgO 0~1.0 CaO 0~1.4 SrO 0~2.5 ZnO 0~1.3 Terbium calculated as Tb4O7 0~2.6 P2O50~6.1 ZrO20~1.0 It contains at least one, preferably all, of:

[0042] It is even more preferred that the glasses and glass ceramics in this embodiment contain 4.7 to 18.5 wt.-% cerium, calculated as CeO2, and 3.7 to 14.5 wt.-% tin, calculated as SnO, in particular 5.3 to 17.9 wt.-% cerium, calculated as CeO2, and 4.1 to 14.0 wt.-% tin, calculated as SnO, more preferably 5.8 to 16.6 wt.-% cerium, calculated as CeO2, and 4.6 to 13.0 wt.-% tin, calculated as SnO, and especially preferred 6.1 to 16.0 wt.-% cerium, calculated as CeO2, and 4.7 to 12.6 wt.-% tin, calculated as SnO.

[0043] The invention also relates to precursors of corresponding composition, from which the glass ceramics according to the invention can be produced by heat treatment. These precursors are correspondingly constituted glasses (also called starting glasses) and glasses containing correspondingly constituted nuclei. The term "corresponding composition" means that these precursors contain the same components and amounts as the glass ceramics, these components, except for fluorine, being calculated as oxides, as is usual for glasses and glass ceramics.

[0044] The present invention also relates to glasses according to the invention which contain nuclei for crystallization. By heat treatment of the glasses according to the invention, glasses with nuclei according to the invention can first be produced, which can then be converted by further heat treatment into glass ceramics according to the invention.

[0045] The invention further relates to glasses according to the invention and glass-ceramics according to the invention, which exhibit a whitish-blue fluorescent colour in the CIE colour space when excited with light having a wavelength of 380 to 430 nm, in particular 395 nm.

[0046] The invention also relates to a process for preparing the glass according to the invention or the glass-ceramic according to the invention, in which tin is used at least partly in divalent form, in particular as SnO.

[0047] In the preparation of the glasses and glass ceramics according to the invention, particularly suitable starting materials, such as mixtures of carbonates, oxides, phosphates and fluorides, are melted. In a preferred embodiment, the starting materials for the components of the glasses and glass ceramics according to the invention are melted at temperatures of 1400-1800° C., in particular 1450-1600° C. and particularly preferably about 1500° C., in particular for 20 min to 10 h. In order to achieve a particularly high homogeneity, the resulting glass melt is poured into water to form glass granules, and the resulting granules are then melted again.

[0048] This melt can be poured into a mould to produce a blank of the starting glass, the so-called solid glass blank or monolithic blank.

[0049] It is also possible to add the melt again to water to produce granules which, after grinding and, if necessary, the addition of further ingredients such as colorants, can then be pressed into blanks, so-called pressed powders.

[0050] Finally, the starting glass can also be processed into a powder after granulation.

[0051] The glass, for example in the form of a solid glass blank, compact or powder, can then be heat treated to produce a nucleated glass, also called a nucleation process. The invention therefore also relates to a process for preparing a nucleated glass, in which the glass is subjected to a heat treatment at a temperature of 450-600° C., and in particular 470-550° C., in particular for a time of 5 min to 120 min, and preferably 10 min to 60 min.

[0052] The glass with the nuclei can then be used to form a glass ceramic according to the invention by heat treatment.The invention therefore also relates to a process for preparing a glass ceramic according to the invention, in which the glass, in particular the glass with the nuclei, is subjected to at least one heat treatment at a temperature between 700 and 950°C, in particular for a time between 5 and 120 minutes, and preferably between 10 and 60 minutes.

[0053] The glasses according to the invention, and the glasses comprising nuclei according to the invention, are preferably in the form of powder or compacts, and are subjected to at least one heat treatment to produce a glass ceramic.

[0054] In a further preferred embodiment, this at least one heat treatment is carried out as part of a sintering-on process, especially of the powder.

[0055] Thus, in a preferred embodiment, the present invention relates to a process for preparing a glass ceramic according to the invention, in which process (a) the powder of the glass according to the invention is pressed into a compact, if necessary after the addition of further components, such as other glasses, glass ceramics and / or pressing aids, and (b) The compact is subjected to a heat treatment at a temperature between 700 and 950° C., in particular for a time between 5 and 120 minutes.

[0056] In this process, nucleation may optionally be carried out prior to the heat treatment in step (b).

[0057] Furthermore, the present invention relates to the use of the glasses according to the invention and the glass ceramics according to the invention with a high content of cerium and tin for adjusting the fluorescence of other glasses and other glass ceramics. Glasses and glass ceramics containing the glasses according to the invention or the glass ceramics according to the invention therefore constitute another subject of the present invention. In this context, glasses and glass ceramics containing the glasses according to the invention or the glass ceramics according to the invention, which contain cerium and tin in an amount of 0.1 to 60% by weight, in particular 1 to 58% by weight, preferably 5 to 56% by weight, particularly preferably 10 to 54% by weight and more preferably 15 to 52% by weight, based on the total amount of the glass or glass ceramic and the glass according to the invention or the glass ceramic according to the invention, are particularly preferred.

[0058] The glasses and glass ceramics with high contents of cerium and tin according to the invention can in particular be used in combination with various other glasses and / or glass ceramics, and these combinations can in particular be used as dental materials. Particularly preferably, these combinations can be in the form of blanks for sintering. Examples of other glasses and glass ceramics for the production of combinations are DE 43 14 817 A1, DE 44 23 793 C1, DE 44 23 794 C1, DE 44 28 839 A1, DE 196 47 739 A1, DE 197 25 552 A1, DE 100 31 431 A1, EP 0 827 941 A1, EP 0 916 625 A1, WO 00 / 34196 A2, EP 1 505 041 A1, EP 1 688 398 A1, EP 2 287 122 A1, EP 2 377 831 A1, EP 2 407 439 A1, WO 2013 / 053863 A2, WO No. 2013 / 053864 A2, WO 2013 / 053865 A2, WO 2013 / 053866 A2, WO 2013 / 053867 A2, WO 2013 / 053868 A2, WO 2013 / 164256 A1, WO 2014 / 170168 A1, WO 2014 / 170170 A2, WO 2015 / 067643 A1, WO 2015 / 155038 A1, WO 2015 / 173394 A1, WO 2016 / 120146 A1, WO 2017 / 032745 A1, WO 2017 / 055010 A1. These glasses and glass ceramics belong to the silicate, borate, phosphate or aluminosilicate groups. Preferred glasses and glass ceramics are of the SiO2-Al2O3-K2O type (with cubic or tetragonal leucite crystals), SiO2-B2O3-Na2O type, alkali silicate type, alkali zinc silicate type, silicophosphate type and / or SiO2-ZrO2 type.Particularly preferred are lithium silicate glass ceramics, and in particular glass ceramics containing lithium metasilicate or lithium disilicate as the main crystalline phase and, if necessary, further crystalline phases such as lithium metasilicate, lithium disilicate, apatite, diopside, spodumene, petalite, eucryptite and / or wollastonite, as well as glass ceramics containing SiO2 as the main crystalline phase, in particular in the form of a low- and / or high-quartz solid solution. By mixing such glasses or glass ceramics with glasses and / or glass ceramics having a high content of cerium and tin according to the invention, in particular the fluorescent properties can be adjusted in the desired manner.

[0059] The glasses according to the invention and the glass ceramics according to the invention are present in any shape and size, in particular in the form of powders, granules, pastes, aerosols or blanks, for example in the form of platelets, cubes or cylinders, or monolithic blanks such as pressed powders, in green, partially sintered or densely sintered form, in particular in the form of combinations. In these forms, they can be easily further processed, for example into dental restorations. However, they can also be in the form of dental restorations, for example as inlays, onlays, crowns, partial crowns, bridges, veneers, occlusal facets or abutments, or as coatings on dental restorations.

[0060] Dental restorations such as inlays, onlays, crowns, partial crowns, bridges, veneers, occlusal facets or abutments can be produced from the glass ceramics according to the invention and the glasses according to the invention, especially in the form of a combination. The invention therefore relates to their use as dental materials and in particular to their use in the preparation of dental restorations. The glass ceramics and glasses are preferably given the shape of the desired dental restoration by pressing, sintering or machining.

[0061] Pressing is usually carried out under elevated pressure and temperature. Pressing is preferably carried out at temperatures between 700 and 1150 ° C, and in particular between 700 and 1000 ° C. Pressing is further preferably carried out at a pressure between 10 and 30 bar. During pressing, the desired change in shape is achieved by the viscous flow of the materials used. The glasses according to the invention and the glasses with nuclei according to the invention, as well as preferably the glass ceramics according to the invention, can be used for pressing. In particular, the glasses and glass ceramics according to the invention can be used in the form of blanks of any shape and size, for example as compacts in unsintered, partially sintered or densely sintered form.

[0062] Machining is usually carried out by a material removal process, and in particular by milling and / or grinding. It is particularly preferred that machining is carried out as part of a CAD / CAM process. The glasses according to the invention, the glasses with nuclei according to the invention, and the glass ceramics according to the invention can be used for machining. In this context, the glasses and glass ceramics according to the invention can in particular be used in the form of blanks, for example in the form of green, partially sintered or densely sintered compacts. Preferably, the glass ceramics according to the invention are used for machining. The glass ceramics according to the invention can also be used in a not yet fully crystallized form, produced by heat treatment at lower temperatures. This gives the advantage of easier machining and therefore the use of simpler equipment for machining. After machining such a partially crystallized material, it is usually subjected to a further heat treatment to induce further crystallization.

[0063] The glass ceramics according to the invention and the glasses according to the invention are also suitable, in particular in the form of combinations, for example, for coating ceramics, glass ceramics and metals. "Coatings" which can be produced using the glasses according to the invention and the glass ceramics according to the invention, in particular in the form of combinations, also mean, for example, glazes.

[0064] The present invention therefore also relates to the use of the glass according to the invention and the glass ceramic according to the invention, in particular in the form of a combination, in particular for coating ceramics, glass ceramics and metals. The coating preferably comprises applying the glass according to the invention or the glass ceramic according to the invention, in particular in the form of a combination, to a substrate material and subjecting this together with the substrate material to a heat treatment at a temperature of at least 600° C., in particular from 600 to 1150° C. and particularly preferably from 700 to 1000° C.

[0065] This can be carried out in particular by oversintering and preferably by overpressing. In the case of oversintering, the glass ceramics and glasses are applied in the usual manner, for example as powder, paste or aerosol, to the material to be coated, for example ceramic, glass ceramic or metal, and then sintered. In a preferred overpressing process, the glass ceramics according to the invention and the glasses according to the invention, for example in the form of pressed powder, are overpressed at high temperatures of 700 to 1150° C., and in particular 700 to 1000° C., and by application of a pressure of, for example, 10 to 30 bar. In particular, the process described in EP 231 773 and the pressing furnaces disclosed therein can be used for this purpose. A suitable commercially available furnace is the Programmat type furnace from Ivoclar Vivadent AG, Liechtenstein.

[0066] Due to the above-mentioned properties of the glass ceramics according to the invention and the glasses according to the invention, they are particularly suitable for use in dentistry. It is therefore also an object of the invention to use the glass ceramics according to the invention and the glasses according to the invention, especially in the form of combinations, as dental materials and in particular for preparing dental restorations such as crowns, bridges and abutments or for coating dental restorations.

[0067] A particularly preferred embodiment is the use for coating dental restorations, in which a substrate material, in particular a glass ceramic, a ceramic or a metal, is coated with the glass according to the invention or the glass ceramic according to the invention, in particular in the form of a combination. Particularly preferred dental restorations are selected from inlays, onlays, crowns, partial crowns, bridges, veneers, occlusal facets and abutments.

[0068] The use for coating dental restorations preferably involves applying the glass according to the invention or the glass ceramic according to the invention, in particular in the form of a combination, to a substrate material and subjecting this together with the substrate material to a heat treatment, preferably at a temperature of at least 600° C., in particular from 600 to 1150° C. and particularly preferably from 700 to 1000° C. The application of the glass according to the invention or the glass ceramic according to the invention, in particular in the form of a combination, is carried out in the usual manner, for example as a powder, paste or aerosol.

[0069] The invention therefore also relates to a process for preparing a dental restoration, in particular an inlay, onlay, crown, partial crown, bridge, veneer, occlusal facet or abutment, in which a glass ceramic or glass according to the invention, in particular in the form of a combination, is given the shape of the desired dental restoration by pressing, sintering or machining, in particular as part of a CAD / CAM process.

[0070] The invention also relates to a process for coating dental restorations, in particular inlays, onlays, crowns, partial crowns, bridges, veneers, occlusal facets or abutments, in which the glass according to the invention or the glass ceramic according to the invention, in particular in the form of a combination, is applied to a substrate material and, together with the substrate material, is subjected to a heat treatment, preferably at a temperature of at least 600° C., in particular from 600 to 1150° C. and particularly preferably from 700 to 1000° C. The application of the glass according to the invention and the glass ceramic according to the invention, in particular in the form of a combination, is carried out in the usual manner, for example as a powder, paste or aerosol. Preferably, the substrate material is a glass ceramic, a ceramic or a metal.

[0071] The invention is explained in more detail below by means of examples, which do not limit the invention. EXAMPLES

[0072] 1. Preparation of fluorescent glass

[0073] Thirty glasses according to the invention were prepared, with the compositions given in Table I. For this purpose, starting glasses with the compositions given in Table I were first melted from common raw materials at 1500° C. for 60 minutes. Glass frits were prepared by pouring the molten starting glasses into water.

[0074] Furthermore, two glasses were produced using the corresponding process as comparative examples, the compositions of which are also given in Table I as Examples 31 and 32. In deviation from the process for the preparation of the glasses of Examples 1 to 30, the melting for the production of Example 31 was carried out at 1650° C. for 240 minutes.

[0075] The glass transition temperatures T are also given in Table I for the glasses according to the invention. g was determined by DSC (differential scanning calorimetry).

[0076] The fluorescence properties of the glass frits were investigated. For this purpose, the glass frits were irradiated in turn with a mercury lamp (excitation wavelength 366 nm) and with a UV LED (excitation wavelength 395 nm) and examined in each case with the naked eye for fluorescence.

[0077] For the glass frits of Examples 1-30, clear fluorescence was perceptible both with mercury lamp excitation and with UV LED excitation.

[0078] The glass frit of Example 31 showed clearly perceptible fluorescence when irradiated with a mercury lamp (excitation wavelength 366 nm). However, no fluorescence was perceptible when excited with a UV LED (excitation wavelength 395 nm). Experiments with the glass frit of Example 32 showed no perceptible fluorescence when irradiated with either a mercury lamp or a UV LED.

[0079] The advantageous fluorescence of the glass frit according to the invention is illustrated in Figure 1, which shows on the right side of the photograph the fluorescent glass frit of Example 3 when excited by a UV LED (excitation wavelength 395 nm). For comparison, a solid glass sheet was produced from the glass frit of Example 31 by carrying out the procedure described in EP 3 696 149 A1 for its Example 5. The process involved remelting the glass frit of Example 31 at 1650°C for 240 minutes. The resulting melt was then poured onto a copper block to produce a solid glass sheet. The solid glass sheet obtained in this way is shown on the left side of the photograph in Figure 1 and does not show fluorescence. [Table 1-1] [Table 1-2] [Table 1-3] 2. Use of fluorescent glass as a blend component

[0080] The glass frits of Examples 3 and 32 were ground in a zirconia mill to a particle size of 45 μm. The ground glass frit of Example 3 was then added as a mixed component to the non-fluorescent ground glass frit of Example 32 in various amounts (20 wt%, 33 wt%, and 50 wt% based on the mixture).

[0081] The various powder mixtures were then pressed into compacts by hydraulic pressing at 15 bar for 10 seconds and sintered at 920° C. for 10 minutes.

[0082] After sintering, the fluorescence properties of the sintered compacts were investigated under mercury lamp (excitation wavelength 366 nm) and UV LED (excitation wavelength 395 nm). The sintered powder blanks showed clearly perceptible fluorescence both when irradiated with mercury lamp and when irradiated with UV LED. It was found that strong fluorescence can be obtained by using a high percentage of fluorescent compound components. 3. Preparation of sintered glass-ceramic blanks

[0083] The glass frits of Examples 9, 10, 15-18, 20, 21, 29 and 30 were milled in a zirconium oxide mill to a particle size of 45 μm. The resulting glass powders were pressed into blanks in a hydraulic press at 15 bar for 10 seconds and sintered in a T Sinter Temperature and t Sinter The glass-ceramic blanks were sintered with a holding time of 100 s to form dense glass-ceramic blanks. The crystalline phases of these glass-ceramic blanks were determined by X-ray diffraction (XRD) analysis. The determination of the mass of these crystalline phases can be carried out by the Rietveld method. A suitable method for this is described, for example, in the article by M. Dittmer "Glasses and glass ceramics in the system MgO-Al2O3-SiO2with ZrO2as nucleating agent", University of Jena 2011.

[0084] Sintering conditions T used for the production of the individual glass-ceramic blanks Sinterand t Sinter , as well as the determined crystalline phases are given in Table II. The term "main crystalline phase" refers to the crystalline phase having the highest mass fraction among all crystalline phases present in the glass-ceramic.

[0085] The fluorescence of the obtained glass-ceramic bodies was determined under a mercury lamp (excitation wavelength 366 nm) and under a UV LED (excitation wavelength 395 nm). All sintered glass-ceramic bodies showed clearly perceptible fluorescence when irradiated with a mercury lamp and also when irradiated with a UV LED.

[0086] The advantageous fluorescence of the glass-ceramic blanks according to the invention is illustrated by Figures 2 and 3. Figure 2 shows, on the right side of the picture, the fluorescence of the glass-ceramic blank of Example 15 when excited with a UV LED (excitation wavelength 395 nm). In Figure 3, the fluorescent glass-ceramic blank of Example 17 when excited with a UV LED (excitation wavelength 395 nm) is shown on the right side of the picture. In Figures 2 and 3, a non-fluorescent solid glass sheet is shown on the left side of each picture, which was produced by the same procedure as the solid glass sheet shown in Figure 1. [Table 2]

Claims

1. 2. Glasses and glass-ceramics containing cerium and tin comprising the following components: Ingredients Weight% Yes ２ 48.00~75.00 Li ２ O 8.0~20.5 CeO ２ Cerium calculated as 4.0-20.0 Tin calculated as SnO 3.1-15.7 Glasses and glass-ceramics comprising:

2. 50.0 to 72.0% by weight, in particular 52.0 to 70.1% by weight and particularly preferably 57.0 to 70.1% by weight of SiO ２ 2. The glass and glass-ceramic of claim 1 , comprising:

3. 9.0 to 19.0% by weight, in particular 10.1 to 18.2% by weight, and particularly preferably 10.9 to 17.3% by weight of Li ２ 3. The glass or glass ceramic according to claim 1, which contains O.

4. 4.3 to 19.0% by weight, preferably 4.7 to 18.5% by weight, in particular 5.3 to 17.9% by weight, more preferably 5.8 to 16.6% by weight, and particularly preferably 6.1 to 16.0% by weight of CeO ２ 4. The glass and glass ceramic according to claim 1, further comprising cerium, calculated as:

5. 5. The glass and glass ceramic according to claim 1 , which contains 3.4 to 14.9 wt.-%, preferably 3.7 to 14.5 wt.-%, in particular 4.1 to 14.0 wt.-%, more preferably 4.6 to 13.0 wt.-%, and particularly preferably 4.7 to 12.6 wt.-% tin, calculated as SnO.

6. CeO ２ 6. The glass and glass ceramic according to claim 1 , wherein the molar ratio of cerium, calculated as SnO, to tin, calculated as SnO, is in the range from 1.5:1 to 1:1.5, preferably from 1.2:1 to 1:1.2 and in particular from 1.1:1 to 1:1.1, and particularly preferably is 1.0:1.

0.

7. The following ingredients in the amounts indicated: Ingredients Weight% Yes ２ 48.00~75.00 Li ２ O 8.0~20.5 CeO ２ Cerium calculated as 4.0-20.0 Tin calculated as SnO 3.1-15.7 Me Ｉ ２ O0~11.5 Me ＩＩ O0~11.0 Me ＩＩＩ ２ O ３ 0~8.0 Me ＩＶ O ２ 0~2.0 Me Ｖ ２ O ５ 0~8.0 Tb ４ O ７ Terbium calculated as 0 to 3.5 Fluorine 0-5.0 wherein the compound contains at least one, and preferably all, of Me Ｉ ２ O is especially Na ２ O.K. ２ O, Rb ２ O and / or CsO ２ is selected from Me ＩＩ O is in particular selected from MgO, CaO, SrO, BaO and / or ZnO, Me ＩＩＩ ２ O ３ Especially B ２ O ３ , Y ２ O ３ , La ２ O ３ , Ga ２ O ３ and / or In ２ O ３ is selected from Me ＩＶ O ２ In particular, ZrO ２ , TiO ２ and / or GeO ２ is selected from Me Ｖ ２ O ５ Especially P ２ O ５ , V ２ O ５ , Ta ２ O ５ and / or Nb ２ O ５ Selected from: Glass and glass ceramic according to any one of the preceding claims.

8. The following ingredients in the amounts indicated: Ingredients Weight% Yes ２ 48.00~75.00 Li ２ O 8.0~20.5 CeO ２ Cerium calculated as 4.0-20.0 Tin calculated as SnO 3.1-15.7 K ２ O 0~11.0 <h2 style=";text-align:left;direction:ltr">Al<h2 style=";text-align:left;direction:ltr"> ２ <h2 style=";text-align:left;direction:ltr"> O<h2 style=";text-align:left;direction:ltr"> ３ <h2 style=";text-align:left;direction:ltr"> 0~8.0 MgO 0-2.0 CaO 0-2.5 SrO 0-4.0 ZnO 0-2.2 Tb ４ O ７ Terbium calculated as 0 to 3.5 P ２ O ５ 0~8.0 ZrO ２ 0~2.0 8. Glasses and glass ceramics according to claim 1, which contain at least one, preferably all, of:

9. 9. The glass according to claim 1, which contains nuclei for crystallization.

10. 10. Glasses and glass ceramics comprising the cerium- and tin-containing glass or glass ceramic according to any one of claims 1 to 9, preferably in an amount of 0.1 to 60% by weight, in particular 1 to 58% by weight, preferably 5 to 56% by weight, particularly preferably 10 to 54% by weight and more preferably 15 to 52% by weight.

11. The glasses and glass ceramics according to any one of claims 1 to 10, wherein the glasses and glass ceramics are in the form of powders, granules, pastes, aerosols, blanks, dental restorations, or coatings on dental restorations.

12. 12. Process for preparing the glasses and glass ceramics according to claim 1, wherein the tin is used at least partly in divalent form, in particular as SnO.

13. 13. The process according to claim 12, wherein the starting materials of the components of the glass or glass ceramic are melted at a temperature of 1400°C to 1800°C, in particular 1450 to 1600°C and particularly preferably about 1500°C, preferably for 20 minutes to 10 hours.

14. 11. Use of the glass or glass ceramic according to claim 1 as a mixture component for adjusting the fluorescence of the glass or glass ceramic.

15. Use of the glass or glass ceramic according to any one of claims 1 to 11 as a dental material, in particular for preparing or coating a dental restoration.

16. 12. A process for preparing a dental restoration, in particular an inlay, onlay, crown, partial crown, bridge, veneer, occlusal facet or abutment, in which a glass or glass ceramic according to any one of claims 1 to 11 is given the shape of the desired dental restoration by pressing, sintering or machining, in particular as part of a CAD / CAM process.

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