Classifications

• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C3/00—Glass compositions
  • C03C3/04—Glass compositions containing silica
  • C03C3/076—Glass compositions containing silica with 40% to 90% silica, by weight
  • C03C3/083—Glass compositions containing silica with 40% to 90% silica, by weight containing aluminium oxide or an iron compound
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C10/00—Devitrified glass ceramics, i.e. glass ceramics having a crystalline phase dispersed in a glassy phase and constituting at least 50% by weight of the total composition
  • C03C10/0009—Devitrified glass ceramics, i.e. glass ceramics having a crystalline phase dispersed in a glassy phase and constituting at least 50% by weight of the total composition containing silica as main constituent
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61C—DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE
  • A61C13/00—Dental prostheses; Making same
  • A61C13/0003—Making bridge-work, inlays, implants or the like
  • A61C13/0022—Blanks or green, unfinished dental restoration parts
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K6/00—Preparations for dentistry
  • A61K6/80—Preparations for artificial teeth, for filling teeth or for capping teeth
  • A61K6/802—Preparations for artificial teeth, for filling teeth or for capping teeth comprising ceramics
  • A61K6/818—Preparations for artificial teeth, for filling teeth or for capping teeth comprising ceramics comprising zirconium oxide
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K6/00—Preparations for dentistry
  • A61K6/80—Preparations for artificial teeth, for filling teeth or for capping teeth
  • A61K6/831—Preparations for artificial teeth, for filling teeth or for capping teeth comprising non-metallic elements or compounds thereof, e.g. carbon
  • A61K6/833—Glass-ceramic composites
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B19/00—Other methods of shaping glass
  • C03B19/02—Other methods of shaping glass by casting molten glass, e.g. injection moulding
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B32/00—Thermal after-treatment of glass products not provided for in groups C03B19/00, C03B25/00 - C03B31/00 or C03B37/00, e.g. crystallisation, eliminating gas inclusions or other impurities; Hot-pressing vitrified, non-porous, shaped glass products
  • C03B32/02—Thermal crystallisation, e.g. for crystallising glass bodies into glass-ceramic articles
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C10/00—Devitrified glass ceramics, i.e. glass ceramics having a crystalline phase dispersed in a glassy phase and constituting at least 50% by weight of the total composition
  • C03C10/0018—Devitrified glass ceramics, i.e. glass ceramics having a crystalline phase dispersed in a glassy phase and constituting at least 50% by weight of the total composition containing SiO2, Al2O3 and monovalent metal oxide as main constituents
  • C03C10/0027—Devitrified glass ceramics, i.e. glass ceramics having a crystalline phase dispersed in a glassy phase and constituting at least 50% by weight of the total composition containing SiO2, Al2O3 and monovalent metal oxide as main constituents containing SiO2, Al2O3, Li2O as main constituents
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C3/00—Glass compositions
  • C03C3/04—Glass compositions containing silica
  • C03C3/076—Glass compositions containing silica with 40% to 90% silica, by weight
  • C03C3/089—Glass compositions containing silica with 40% to 90% silica, by weight containing boron
  • C03C3/091—Glass compositions containing silica with 40% to 90% silica, by weight containing boron containing aluminium
  • C03C3/093—Glass compositions containing silica with 40% to 90% silica, by weight containing boron containing aluminium containing zinc or zirconium
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C3/00—Glass compositions
  • C03C3/04—Glass compositions containing silica
  • C03C3/076—Glass compositions containing silica with 40% to 90% silica, by weight
  • C03C3/095—Glass compositions containing silica with 40% to 90% silica, by weight containing rare earths
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C3/00—Glass compositions
  • C03C3/04—Glass compositions containing silica
  • C03C3/076—Glass compositions containing silica with 40% to 90% silica, by weight
  • C03C3/097—Glass compositions containing silica with 40% to 90% silica, by weight containing phosphorus, niobium or tantalum
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C4/00—Compositions for glass with special properties
  • C03C4/0007—Compositions for glass with special properties for biologically-compatible glass
  • C03C4/0021—Compositions for glass with special properties for biologically-compatible glass for dental use
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P40/00—Technologies relating to the processing of minerals
  • Y02P40/50—Glass production, e.g. reusing waste heat during processing or shaping

Definitions

• the invention relates to a process for the preparation of a lithium silicate glass blank having a composition with at least 8% by weight, preferably 9 to 20% by weight, of a stabilizer from the group ZrO 2 , HfO 2 or mixtures thereof.
• the invention also relates to a method for producing a lithium silicate glass-ceramic blank and the use of the lithium silicate glass-ceramic blank.
• the invention also refers to the use of the lithium silicate glass-ceramic blank and to a dental product.
• Blanks of lithium silicate glass-ceramic have proven themselves in the field of dental technology due to their strength and biocompatibility. This shows the advantage that when a lithium silicate blank contains lithium metasilicate as the main crystal phase, a problem-free machining is possible without a high tool wear occurs. Then, a heat treatment in which the product is converted into a lithium disilicate glass-ceramic results in high strength. There are also good optical properties and good chemical stability. Corresponding methods can be found in DE 197 50 794 A1 or DE 103 36 913 B4.
• the strength is increased and a good translucency can be achieved if the starting raw materials in the form of lithium carbonate, quartz, alumina etc., ie customary starting components, at least one stabilizer from the group zirconium oxide, hafnium oxide or mixtures thereof, in particular zirconium oxide, is added.
• the weight fraction of the stabilizer in the starting mixture can be up to 20%.
• the present invention is u. a. the object of providing a method for producing a lithium silicate glass blank is available, which ensures that the stabilizer is not recrystallized during the subsequent heat treatment, especially when lithium disilicate should be present as the main crystal phase.
• the melt to be filled can be molded on an industrial and reproducible scale into, in particular, dental products such as press pellets or blocks to be machined by means of CAD / CAM methods. It is intended to prevent a so-called "high sloshing" of the melt in the interior of the mold during filling of the molds, so that the desired smooth, horizontally extending surface of the solidified molding would not be achievable.
• the invention provides a process for preparing a lithium silicate glass blank having at least 8% by weight, preferably 9 to 20% by weight of a stabilizer from the group Zr0 2 , Hf0 2 or mixtures thereof, which comprises the process steps includes:
• the invention is also distinguished by a process for the preparation of a lithium silicate glass blank having a composition with at least 8% by weight, preferably 9 to 20% by weight, of a stabilizer from the group Zr0 2 , Hf0 2 or mixtures thereof, with the steps:
• a process for producing a lithium silicate glass blank having a composition with at least 8% by weight, preferably 9 to 20% by weight, of a stabilizer from the group ZrO 2 , HfO 2 or mixtures thereof comprises the process steps:
• the invention also relates to a process for the preparation of a lithium silicate glass blank having a composition with at least 8% by weight, preferably 9 to 20% by weight, of a stabilizer from the group ZrO 2 , HfO 2 or mixtures thereof, the process comprising Steps includes:
• the invention relates to a process for producing a lithium silicate glass blank having a composition having at least 8% by weight, preferably 9 to 20% by weight, of a stabilizer from the group Zr0 2 , Hf0 2 or mixtures thereof, comprising the process steps
• the stabilizer powder in particular zirconium oxide powder
• zirconia goes well in solution and remains there, ie in the amorphous phase, ie Glass is present, even if the melt is filled into the mold, cooled and then subjected to one or more heat treatments to form at least lithium disilicate crystals.
• the data ds 0 , d 10 , d 90 mean that 50%, 10% and 90% of the particles have a particle size which is smaller than the specified value of the particle size.
• the melt By cooling the melt compared to the temperature at which the starting materials are melted and homogenized by thermal without the need for mechanical aids such as stirrers, there is the advantage that the melt has a viscosity that facilitates the reproducible filling of the molds simultaneous achievement of a horizontal surface allows.
• the prevention of recrystallization may also be assisted by cooling the melt in the mold at a cooling rate in the range between 5 K / sec and 100 K / sec, thereby preventing nuclei from forming for the stabilizer material.
• the cooling rate applies at least up to a temperature T M > 600 ° C, in particular 600 ° C ⁇ T M ⁇ 650 ° C. Subsequently, a cooling to room temperature in the usual manner.
• the melt at the temperature T AU which is between 1500 ° C and the heat resistance of the crucible material used, such as platinum alloy, over a period of at least 1 hour, in particular over a period of between 2 and 7 hours.
• T AU the melt at the temperature T AU
• the heat resistance of the crucible material used such as platinum alloy
• the invention is therefore also distinguished by the fact that, after melting of the raw materials in the container and homogenization in this, in particular by thermal, the melt is filled directly into the containers.
• the invention and in contrast to the prior art, is preferably characterized in that the production of a frit and the remelting of these are not required, without resulting in disadvantages with respect to homogenization.
• a shorter process time or a more cost-effective production of the blank in comparison to the prior art, in principle, a shorter process time or a more cost-effective production of the blank.
• the melt in the container which is homogenized by thermal, is cooled during the homogenization.
• the melt z. B. initially over a period of 2 to 6 hours at a temperature Ti with 1450 ° C ⁇ T ⁇ 1550 ° C and then over a time t 2 at a temperature 1200 ° C ⁇ t 2 ⁇ 1300 ° C are held, then to be poured or filled to fill the molds.
• the stabilizer contains more than 90% by weight Zr0 2 , in particular more than 95% by weight Zr0 2 , preferably more than 97.5% by weight Zr0 2 .
• composition of the blank in Gew.- the following components:
• the additive may be at least one group oxide: BaO, CaO, MgO, MnO, Er 2 0 3 , Pr 6 On, Sm 2 0 3 , Ti0 2 , V 2 0 5 , Y 2 0 3
• the invention is characterized by a method for producing a lithium silicate glass-ceramic blank using the lithium silicate glass blank produced according to one or more of those previously explained Steps, wherein the filled in the containers and cooled in this melt at least a first heat treatment Wl is subjected to a temperature Twi over a period t W i, wherein 620 ° C ⁇ T W i ⁇ 800 ° C, especially 650 ° C. T W i ⁇ 750 ° C, and / or 1 min ⁇ t W i ⁇ 200 min, preferably 10 min ⁇ t W i ⁇ 60 min.
• a corresponding lithium silicate glass-ceramic blank can be machined without problems, whereby the tool wear is minimal. Also, a corresponding blank can be pressed into a desired geometry.
• the lithium silicate glass-ceramic blank after the first heat treatment Wl of a second heat treatment W2 at a temperature T W2 over a period of time tw 2 wherein 800 ° C. ⁇ Tw 2 ⁇ 1040 ° C., preferably 800 ° C. ⁇ Tw 2 ⁇ 900 ° C., and / or 5 min ⁇ tw 2 ⁇ 200 min, preferably 5 min ⁇ tw 2 ⁇ 30 min , is.
• the following temperature values and heating rates are preferably selected for the heat treatment steps leading to nucleation and precrystallization or final crystallization.
• first heat treatment it is provided in particular that this takes place in two stages, wherein a first holding stage in the range between 640 ° C and 680 ° C and a second holding stage between 720 ° C and 780 ° C.
• the heated molding is held for a period of time, wherein in the first stage a period is preferably between 35 and 45 minutes and in the second stage between 15 and 25 minutes.
• Corresponding lithium silicate glass ceramic blanks have a high translucency and chemical resistance. They are also characterized by their strength. An excretion of stabilizer material, in particular zirconium oxide is not detectable. Therefore, corresponding lithium silicate glass ceramic blanks are particularly suitable as dental materials or components thereof, wherein molded dental products in the form of z. As inlays, onlays, bridges, veneers, veneers, facets, crowns, partial crowns, abutments can be used.
• lithium silicate glass-ceramic blanks exhibit extremely good machining by means of CAD / CAM, wherein after the further heat treatment a highly transparent and high-strength product is available which has a high chemical resistance.
• Raw materials such as lithium carbonate, quartz, alumina, zirconia were mixed on an industrial scale by means of a tumble mixer until a visually uniform mixture was obtained. A total of 5 mixtures were produced, which differed in that the zirconia had different values in grain size.
• composition of the specimens for the experiments carried out in Gew.- was the following:
• the batch was melted in a high temperature platinum alloy crucible for a period of 2.25 hours at 1450 ° C.
• the melt was then cooled, first kept at 1450 ° C for half an hour and then at 1250 ° C for half an hour. Subsequently, the melt was poured into molds suitable for press pellets or blocks of 1 cm 3 to 2 cm 3 in volume for machining.
• the cooling rate was 70 K / sec to 600 ° C. then it was cooled to room temperature. It showed an amorphous and therefore transparent glass.
• the moldings were then subjected to a crystallization firing, wherein in a first heat treatment the moldings were kept at 660 ° C. for 60 minutes and then at 850 ° C. for 8 minutes in a second heat treatment. It was then cooled to room temperature. Examination of the glass-ceramic revealed individual zirconia precipitations, which made the glass-ceramic opaque.
• Press pellets or blocks of a volume of 1 cm 3 to 2 cm 3 are suitable for machining.
• the cooling rate was 70 K / sec to 600 ° C. Then it was cooled to room temperature. It showed an amorphous and therefore transparent glass.
• the moldings were subjected to a crystallization firing subjected.
• the glass was first heated from room temperature at a heating rate of 2 K / min to 660 ° C and held at this temperature for 40 minutes. Subsequently, a further heating to 750 ° C with a heating rate of 10 K / min. The holding time was 20 minutes. Subsequently, the final crystallization takes place at a temperature of 850 ° C for 8 minutes. It was then cooled to room temperature. In a review of the glass ceramic zirconia precipitates were found.
• the batch was melted in a high temperature platinum alloy crucible for 6 hours at 1500 ° C.
• the melt was then cooled and kept at 1250 ° C for half an hour.
• the melt was poured into molds suitable for press pellets or blocks of 1 cm 3 to 2 cm 3 in volume for machining.
• the cooling rate was 70 K / sec to 600 ° C. It was then cooled to room temperature. It showed an amorphous and therefore transparent glass.
• the shaped bodies were then subjected to a crystallization firing. For nucleation or precrystallization, the glass was first heated from room temperature at a heating rate of 2 K / min to 660 ° C and held at this temperature for 40 minutes.
• the batch was melted in a high temperature platinum alloy crucible for 6 hours at 1500 ° C. The melt was then cooled and held at 1200 ° C for half an hour. Subsequently, the melt was poured into molds suitable for press pellets or blocks of 1 cm 3 to 2 cm 3 in volume for machining. The cooling rate was up to 600 ° C 70 K / sec. It was then cooled to room temperature. It showed an amorphous and therefore transparent glass. The shaped bodies were then subjected to a crystallization firing. The glass was first heated from room temperature at a heating rate of 2 K / min to 660 ° C and held at this temperature for 40 minutes.
• the batch was melted in a high temperature platinum alloy crucible for 4 hours at 1500 ° C. The melt was then held at 1450 ° C for 1 hour. Subsequently, the melt was poured into molds suitable for press pellets or blocks of 1 cm 3 to 2 cm 3 in volume for machining. The cooling rate up to 600 ° C was 70 K / sec. It was then cooled to room temperature. It was found an amorphous and thus transparent glass.
• the moldings were then subjected to a crystallization firing, wherein in a first heat treatment, the moldings were kept for 60 minutes at 620 ° C (precrystallization) and then in a second heat treatment for 8 minutes at 850 ° C (final crystallization). It was then cooled to room temperature. A review of the glass-ceramic revealed numerous small zirconia precipitations, which made the glass-ceramic opaque.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Organic Chemistry (AREA)
• Materials Engineering (AREA)
• Ceramic Engineering (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Geochemistry & Mineralogy (AREA)
• General Chemical & Material Sciences (AREA)
• Oral & Maxillofacial Surgery (AREA)
• Crystallography & Structural Chemistry (AREA)
• Epidemiology (AREA)
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• Plastic & Reconstructive Surgery (AREA)
• Molecular Biology (AREA)
• Manufacturing & Machinery (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Dentistry (AREA)
• Glass Compositions (AREA)
• Dental Prosthetics (AREA)
• Re-Forming, After-Treatment, Cutting And Transporting Of Glass Products (AREA)

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• 2014
  • 2014-03-28 DE DE102014104401.0A patent/DE102014104401A1/de not_active Withdrawn
• 2015
  • 2015-03-27 BR BR112016021849-3A patent/BR112016021849B1/pt not_active IP Right Cessation
  • 2015-03-27 ES ES15715195T patent/ES2925020T3/es active Active
  • 2015-03-27 RU RU2016142264A patent/RU2660849C2/ru active
  • 2015-03-27 JP JP2016559594A patent/JP6585075B2/ja active Active
  • 2015-03-27 KR KR1020167030215A patent/KR101968076B1/ko active Active
  • 2015-03-27 WO PCT/EP2015/056675 patent/WO2015144866A1/de not_active Ceased
  • 2015-03-27 CN CN201580028103.1A patent/CN106715345B/zh active Active
  • 2015-03-27 US US14/671,253 patent/US9701572B2/en active Active
  • 2015-03-27 AU AU2015238275A patent/AU2015238275B2/en active Active
  • 2015-03-27 EP EP15715195.2A patent/EP3122691B1/de active Active
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