CA2070691A1 - Method for the manufacture of a priming material - Google Patents
Method for the manufacture of a priming materialInfo
- Publication number
- CA2070691A1 CA2070691A1 CA002070691A CA2070691A CA2070691A1 CA 2070691 A1 CA2070691 A1 CA 2070691A1 CA 002070691 A CA002070691 A CA 002070691A CA 2070691 A CA2070691 A CA 2070691A CA 2070691 A1 CA2070691 A1 CA 2070691A1
- Authority
- CA
- Canada
- Prior art keywords
- priming material
- glass powder
- zirconium dioxide
- mixture
- opacifier
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
- A61K6/00—Preparations for dentistry
- A61K6/15—Compositions characterised by their physical properties
- A61K6/16—Refractive index
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
- A61K6/00—Preparations for dentistry
- A61K6/15—Compositions characterised by their physical properties
- A61K6/17—Particle size
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
- A61K6/00—Preparations for dentistry
- A61K6/20—Protective coatings for natural or artificial teeth, e.g. sealings, dye coatings or varnish
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
- A61K6/00—Preparations for dentistry
- A61K6/70—Preparations for dentistry comprising inorganic additives
- A61K6/78—Pigments
-
- 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
- A61K6/816—Preparations for artificial teeth, for filling teeth or for capping teeth comprising ceramics comprising titanium 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
- A61K6/802—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
- A61K6/802—Preparations for artificial teeth, for filling teeth or for capping teeth comprising ceramics
- A61K6/822—Preparations for artificial teeth, for filling teeth or for capping teeth comprising ceramics comprising rare earth metal oxides
-
- 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
- A61K6/84—Preparations for artificial teeth, for filling teeth or for capping teeth comprising metals or alloys
Abstract
ABSTRACT OF THE DISCLOSURE
A priming material and method of manufacturing same is disclosed for the overlaying or coating of metallic tooth crowns or bridges. The priming material is a mixture of a matrix forming glass powder, an opacifier and a liquid. The opacifier is zirconium dioxide 10 to 60 wt.-% with an average particle size of 1 µm ? 0.2 and a specific surface of about 1 to 20 m2/g.
A priming material and method of manufacturing same is disclosed for the overlaying or coating of metallic tooth crowns or bridges. The priming material is a mixture of a matrix forming glass powder, an opacifier and a liquid. The opacifier is zirconium dioxide 10 to 60 wt.-% with an average particle size of 1 µm ? 0.2 and a specific surface of about 1 to 20 m2/g.
Description
207~
A METHOD FOR THE MANUFACTURE OF A PRIM:tN(~ MATERI~L
The invention relates to a method for the manufacture of a priming material for the o~erlayinq or coating of a metallic tooth crown or bridge, and also to a priming material which contains a matrix-forming glass powder and an opacifier.
When manufacturing metal tooth crowns and bridges which are faced with plastics or ceramic material, it is necessary to overlay ~he metal framework with a priming material - a ~called opaquer -in order that the dark metallic ground is covered and the metal does not gleam through. Without such an opaquer the colour of the finished facing, which is to match the colour of the remainder of the denture as closely as possible, cannot be exactly reproduced.
Known from DE-PS 33 32 179 are priming materials for dental purposes based on polymerizable methacrylic acid esters which contain a mixture of titanium dioxide and zirconium dioxide as pigment, in which a considerable titanium dioxide content, namely of up to 50 wt. %, is provided. The priming materials of ~he examples contain 25 wt.-~ titanium dioxide. They are used to cover metal frameworks for crowns with plastics facings.
The prior art cited in column 2 of this published document, namely Kirk-Othmer, Encyclopedia of Chemical Technology, 2nd edition, New York (1970), Volume 22, 651-653, reveals that the use of zirconium dioxide as ceramic opacifier and as pigment or opacifiex for ceramic glazes and enamels was known. There is no suggestion however that zirconium dioxide be used as an additive for a metal ceramic opaquer, i.e. for a ceramic, in particular glass ceramic priming material for the overla~ing of metal crowns or bridges, where it must be borne in mind that such an opaquer .
.. . ' ' ~ ~ . .
.
.
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must satisfy special requirements. For example, such an opaquer must be deposited on a crown in thin layers of at most 0.5 mm and then be capable of being stoved, the crown to be completaly covered by the brightly gleaming opaquer layer after stoving.
DE-PS 37 43 609 describes a light-permeable glass ceramic which comprises fine crystals of calcium phosphate which are uniformly dispersed in a glass matrix based on SiO2-A102-ZrO2. It is important as bio-material and has advantageous thermal, electrical and mechanical properties. The glass ceramic is transparent or semi-transparent. Zirconium dioxide is added as nucleation or germination agent. The glass ceramic can be used as adhesive or binder for ceramic mass materials or metals.
There is no reference in this publication to the use of a zirconium dioxide-containing glass ceramic as opaquer for the dental sector. What is essential, quite to the contrary, is the light permeability of the glass ceramic, ~or which reason this publication teaches precisely the opposite oE what one skilled in the art expects from an opaquer.
EP-PS 119 062 discloses pasty materials made from porcelain powder and water with added ceramic particles of a par~icle size below O.3~. The materials can be used as opaquer for crowns with porcelain facings.
Known from DE-OS 3 902 771 is a stovable silicatic material for the manufacture of dentures which serves as connection material and for the masking of the metallic colour alloy surface. The object to be achieved should be to provide a silicat~ic material which consists of a readily flowing base melt and a proportion of opaquer, the composition and expansion coefficient of which are set in such a way that it is stovable onto a dental prosthesis section which can be manufactured from noble metal alloys of th0 silver/palladium type or from dental non-metal alloys of the base t~pes nickel/ chromium and cobalt/chromium, '~ .
~73~9~
and forms a gap-free connection to a dental plastics material after its silanization. The silicatic material proposed here is distinguished by a high titanium dioxide content (15.0 - 16.5 wt.-%) and relatively small zirconium dioxide contents (4 to 5 wt.-%).
The disadvantages of the opaquers of DE-PS 33 32 179, EP-PS 119 062 and DE-OS 39 02 771 are lack of covering power and adhesion.
In the crown edges sector in particular, the skoving of the known opaquers is followed by unwanted discolorations which seriously impair the cosmetics of the succeed;ng facings. This is also true of the opaquers known to one skilled in the art which have been commercially available for some time.
~5 The object of the invention is to make available a method for the manufacture of a priming material for dental purposes, namely for the overla~ing or coating of dental metal frameworks prior to facing and also a priming material in particular for ceramics facings with improved covering power and adhesion, the adhesion of which both to metal and to the facing ceramic is excellent, which can be easily applied and stoved and which, particularly ; in the area of the crown edges, reliably covers the metal. The discolorations occurring above all with NE alloys (non-noble metal alloys) are also to be avoided after the stoving.
It was now surprisingly discover~d that by adding larger quantities of zirconium dioxide as opacifier to glass powders one obtains mixtures from which opa~uers can be manufactured which have outstanding properties and guarantee a good covering of the 3~ metal framework and good adhesion to the metal and to the facing.
~lthough the said prior art reveals that zirconium dioxid~ was .
.
: .
.
A METHOD FOR THE MANUFACTURE OF A PRIM:tN(~ MATERI~L
The invention relates to a method for the manufacture of a priming material for the o~erlayinq or coating of a metallic tooth crown or bridge, and also to a priming material which contains a matrix-forming glass powder and an opacifier.
When manufacturing metal tooth crowns and bridges which are faced with plastics or ceramic material, it is necessary to overlay ~he metal framework with a priming material - a ~called opaquer -in order that the dark metallic ground is covered and the metal does not gleam through. Without such an opaquer the colour of the finished facing, which is to match the colour of the remainder of the denture as closely as possible, cannot be exactly reproduced.
Known from DE-PS 33 32 179 are priming materials for dental purposes based on polymerizable methacrylic acid esters which contain a mixture of titanium dioxide and zirconium dioxide as pigment, in which a considerable titanium dioxide content, namely of up to 50 wt. %, is provided. The priming materials of ~he examples contain 25 wt.-~ titanium dioxide. They are used to cover metal frameworks for crowns with plastics facings.
The prior art cited in column 2 of this published document, namely Kirk-Othmer, Encyclopedia of Chemical Technology, 2nd edition, New York (1970), Volume 22, 651-653, reveals that the use of zirconium dioxide as ceramic opacifier and as pigment or opacifiex for ceramic glazes and enamels was known. There is no suggestion however that zirconium dioxide be used as an additive for a metal ceramic opaquer, i.e. for a ceramic, in particular glass ceramic priming material for the overla~ing of metal crowns or bridges, where it must be borne in mind that such an opaquer .
.. . ' ' ~ ~ . .
.
.
~7~
must satisfy special requirements. For example, such an opaquer must be deposited on a crown in thin layers of at most 0.5 mm and then be capable of being stoved, the crown to be completaly covered by the brightly gleaming opaquer layer after stoving.
DE-PS 37 43 609 describes a light-permeable glass ceramic which comprises fine crystals of calcium phosphate which are uniformly dispersed in a glass matrix based on SiO2-A102-ZrO2. It is important as bio-material and has advantageous thermal, electrical and mechanical properties. The glass ceramic is transparent or semi-transparent. Zirconium dioxide is added as nucleation or germination agent. The glass ceramic can be used as adhesive or binder for ceramic mass materials or metals.
There is no reference in this publication to the use of a zirconium dioxide-containing glass ceramic as opaquer for the dental sector. What is essential, quite to the contrary, is the light permeability of the glass ceramic, ~or which reason this publication teaches precisely the opposite oE what one skilled in the art expects from an opaquer.
EP-PS 119 062 discloses pasty materials made from porcelain powder and water with added ceramic particles of a par~icle size below O.3~. The materials can be used as opaquer for crowns with porcelain facings.
Known from DE-OS 3 902 771 is a stovable silicatic material for the manufacture of dentures which serves as connection material and for the masking of the metallic colour alloy surface. The object to be achieved should be to provide a silicat~ic material which consists of a readily flowing base melt and a proportion of opaquer, the composition and expansion coefficient of which are set in such a way that it is stovable onto a dental prosthesis section which can be manufactured from noble metal alloys of th0 silver/palladium type or from dental non-metal alloys of the base t~pes nickel/ chromium and cobalt/chromium, '~ .
~73~9~
and forms a gap-free connection to a dental plastics material after its silanization. The silicatic material proposed here is distinguished by a high titanium dioxide content (15.0 - 16.5 wt.-%) and relatively small zirconium dioxide contents (4 to 5 wt.-%).
The disadvantages of the opaquers of DE-PS 33 32 179, EP-PS 119 062 and DE-OS 39 02 771 are lack of covering power and adhesion.
In the crown edges sector in particular, the skoving of the known opaquers is followed by unwanted discolorations which seriously impair the cosmetics of the succeed;ng facings. This is also true of the opaquers known to one skilled in the art which have been commercially available for some time.
~5 The object of the invention is to make available a method for the manufacture of a priming material for dental purposes, namely for the overla~ing or coating of dental metal frameworks prior to facing and also a priming material in particular for ceramics facings with improved covering power and adhesion, the adhesion of which both to metal and to the facing ceramic is excellent, which can be easily applied and stoved and which, particularly ; in the area of the crown edges, reliably covers the metal. The discolorations occurring above all with NE alloys (non-noble metal alloys) are also to be avoided after the stoving.
It was now surprisingly discover~d that by adding larger quantities of zirconium dioxide as opacifier to glass powders one obtains mixtures from which opa~uers can be manufactured which have outstanding properties and guarantee a good covering of the 3~ metal framework and good adhesion to the metal and to the facing.
~lthough the said prior art reveals that zirconium dioxid~ was .
.
: .
.
2~7~6~
known as an opacifier for ceramic glazes, the use of larger quantities of zlrconium dioxide as primarily ~hesole opacifier addition to glass powders for the manufacture of an opaquer is neither known nor suggested. It was, rather, surprising that in the case of compositions which are free from larger proportions of titanium dioxide and/or other opacifiers and contain zirconium oxide as opacifier additi~e to glass powders one obtains opa~uers which are distinguished by outstanding properties, especially outstanding covering power and adhesion.
The method according to the invenkion comprises the use of a mixture which contains a matrix forming glass powder which is mixed with 10 to 60 wt.-% zirconium dioxide as opacifier. The composition is free from larger proportions of titanium dioxide and/or other opacifiers, i.e. the mixture of glass powder and zirconium dioxide is to contain, at most, 0 to 5 wt.-% titanium dioxide and/or other opacifier.
The glass preferably consists primarily of the oxides o~
sodium, potassium, calcium, barium, boron, aluminium and/or silicon with a small proportion of titanium, the TiO2 optionally present being melted in the glass and functioning, not as an opacifier, but as a germination agent for the crystallization of leucite. Oxides of cerium and optionally of P and Zr may also be contained in the glass. The glass preferably contains as main constituents SiO2, Al203 and K2O, preferably in respective amounts of 40 to 70 wt.-%, 10 to 25 wt.-% and 8 to 28 wt.-%. Other glasses can also be used.
To manufacture the glass, the oxide mixture is melted, quenched in water and worked up in a manner known per se into a fine glass powder.
In detail, for example, the molten oxide mixture is quenched in water and ground up in a ball mill. The glass powder is then .
, 207~9~
tempered at ca. 900 degrees C, sintering together to form a block which is quenched in water while still glowing. A granulate forms which is ground up in an alcohol/water mixture in the ball mill. The result is a slip which is dried and then passed through a screen.
This glass powder is mixed with zirconium dioxide. The mixture is manufactured in the ratio of, at most, 9 parts glass per part zirconium dioxide. Preferred mixture ratios lie between 4:1 and 1:1.5.
To manufacture the ready-to-use opaquer, the powder mixture is mixed with a liquid. For example, the powder can be admixed with distilled water on a ceramic plate to produce an opaquer.
However, other liquids such as glycerin or glycol can also be used for the admixing process.
In a particularly preferred embodiment, 3 parts by weight glass are mixed with 2 parts by weight zirconium dioxide and homogenized with a further 2 parts by weight glycerin on a triple roll mill.
For application as priming material, the resultant paste is deposited on a crown with a brush and stoved at temperatures of between 800 and 1000 degrees C. The result is a covering white layer which displays no discolorations even at the metal edges, is distinguished by a high covering power and offers good adhesion between metal and ceramic. The crown is then faced with ceramic by conventional methods.
Colour pigments can optionally be added to the powder mixture in order to endow the stoved opaquer with a tooth colour-like colour. The colouring substances can also be added during homogenization, however.
:. .
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It is also possible to add other known ceramic powders to the glass powder in order to vary the coefficient of thermal expansion (CTE). The CTE value is known to be an important parameter in metal ceramic facing work and must suit the alloy which is to be faced.
The zirconium dioxide particles have an average particle size of 1 ~m + 0.2. The zirconium dioxide particles also have a specific surface of about 1 to 20 mZ/g and a purity o 99% +/- 1.
The following examples explain the invention.
Example ~
Manufacture of a melt A with high CTE:
glass of the following composition was melted in the usual way:
5.95 wt.-% Na20 13.86 wt.-% K20 3.48 wt.-% CaO
1.64 wt.-% BaO
1.36 wt.-% B203 16.09 wt.-% Al203 0.37 wt.-% TiO2 57.25 wt.-% SiO2.
.
This glass was quenched in water and ground up in a ball mill until the average granulation was ca. 80 to lOO um.
The glass powder was then tempered for an hour at 900 degrees C, sintering together to produce a block which was quenched in water while still glowing. The resultant granulate was ground up to an average granulation of below 20 ~ in an alcohol/ water mixture (1:1) in the ball mill. The grinding time depends on the size and type of the ball mill.
6 ~ ~
For example 200 g coarse glass powder 800 g porcelain balls with 9 mm diameter 100 g distilled water 100 g alcohol were allowed to run on rolls for 8 hours in a 1-1 porcelain drum.
The resulting slip was dried at 100 degrees C and passed through a 60-um screen to avoid agglutinated lumps.
60 g of this melt were mixed with 40 g zirconium dioxide with an average granulation of 1 ~ which is marketed by Magnesium Elektron under the trade mark "Zirkonoxid SC15".
This mixture was blended with 40 g glycerin to form a paste and homogenized on a salve triple roll. The homogenized paste was painted onto a nickel/chromium alloy with a brush and then stoved at 960 degrees C with a 2-minute holding time. The result was a covering white matt layer of very good adhesive~
strength which could then be overlaid with ceramic dental materials. The coating also displayed no discolorations even at the metal edges.
Samples were burned in order to check the strength and the CTE.
The following values were measured:
Bending strength 143 +/- 11 N/mmZ
Flexural modulus 73000 +/- 6000 N/mm CTE 100 - 500 degrees C 14.4 x 10 /K
Example 2 Using the melt A referred to in Example 1, a paste was manufactured according to the following formulation and homogenized as in Example 1:
g melt A
g zirconium dioxide SC15 g ceramic colour 23264 *
.. ~ , ~.
.. . .
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g ceramic colour 26077 **.
0.5 g ceramic colour 14-R-481 ***
2 g SiO2, BET surface 200 ~/- 25 (Aerosil 200 [R] Degussa) g glycerin.
- * orange-yellow, based on Zr and V oxide (Degussa) ** yellow-brown, based on Zr, Cr, Fe, Al oxide (Degussa) *** dark brown, based on Si, Co, Ni, Zn, Fe, Cr, Mn oxide (Ferro) A creamy paste was obtained which could be spread well with the brush. After burning on a nickel/chromium alloy at 960 degrees C a covering, tooth-coloured layer was obtained the colour of 15 which is the same all over.
Bending strength 161 +/- 23 N/mm Flexural modulus 67000 ~/- 2000 N/mm CTE 100 - 500 degrees C 15 x 10 /K.
Example 3 An Ivoclar ceramic powder, usual for metal ceramics, for melt configuration with a CTE 100-600 degrees C of 13.5 x 106/K, a 25 glass point of 585 degrees C and a dilatometer softening point of 600 degrees C was ground wet to an average grain size o < 20 r, dried and deagglomerated by screening as described in Example 1. This powder was named GM-DS.
3~ The following mixture was manufactured:
35 g melt A from Example 1 25 g GM-DS
21 g zirconium dioxide SC15 35 14 g ceramic colour 23264 g ceramic colour 26077 , `
~1~7~
g The mixture was intimately m}xed in a ball mill. It was processed by mixing 1 g of this mixture with water and depositing on a nickel/chromium alloy with a brush. The appearance was the same as in Example 2, except that a glossier surface was obtained. Testing of the CTE value between 100 and 500 degrees C gave a result of 14.5 x 106/K, which shows that the CTE value can be varied by adding other ceramic materials.
Example 4 (comparative examPle with ~L~a~L~
In order to compare the covering power with other opacifiers, the following mixture was manufactured and processed as described in Example 1:
60 g melt A from Example 1 25 g annealed tin dioxide 17 g ceramic colour 23264 11 g ceramic colour 26077 45 g glycerin Processing of this mixture produced an inadequately covering layer in which the black oxides of the nickel/chromium alloy falsified the colour. Because of the high tin dioxide content, the burning temperature of this mixture was already at 1100 degrees C, which is at the upper limit for the stoving alloys usual in dental engineering. The mixture also became discoloured when stored in the light.
Example 5 (comparison with various opacifiers!
In order to compare the covering power wi~h titanium dioxide, a special glass had to be melted and worked up as indicated in Example 1 for melt A. The melt~ named melt B, had the following composition:
. . .
: .
2~7~
7.12 g Na20 11.82 g K20 3.2 g CaO
1.51 g BaO
1.25 g B203 14.5 g A1203 0.34 g TiO2 59.35 g SiO2 10 The following mixture was manufactured as in Example 1:
70 g melt B
30 g opacifier 15 40 g glycerin The following table contains the opacifiers used and the test results for the processing on nickel/chromium alloys:
Opacifier Processing Covering Discoloration consistency power upon stoving Titanium 25 diOxide AD good very good dark grey Titanium dioxide R-KB-2 good very good grey/brown Titanium dioxide RN-56 good very good grey/brown Precipitated 30 tin oxide pasty inadequate white Zirconium ~nn ~ dioxide > 1 ~¢ liquid inadequate white ffh~ Zirconium silicate pasty inadequate white The discolorations in the case of the samples with titan.ium dioxide were uneven and clearly more marked towards the mei~.al edge, so that this discoloration was unacceptable after stoving.
2~7~
~L "~
The samples with tin oxide, zirconium dioxide > 1 ~ and zirconium silicate had an inadequate co~ering power and were likewise not acceptable.
. . . .
.
known as an opacifier for ceramic glazes, the use of larger quantities of zlrconium dioxide as primarily ~hesole opacifier addition to glass powders for the manufacture of an opaquer is neither known nor suggested. It was, rather, surprising that in the case of compositions which are free from larger proportions of titanium dioxide and/or other opacifiers and contain zirconium oxide as opacifier additi~e to glass powders one obtains opa~uers which are distinguished by outstanding properties, especially outstanding covering power and adhesion.
The method according to the invenkion comprises the use of a mixture which contains a matrix forming glass powder which is mixed with 10 to 60 wt.-% zirconium dioxide as opacifier. The composition is free from larger proportions of titanium dioxide and/or other opacifiers, i.e. the mixture of glass powder and zirconium dioxide is to contain, at most, 0 to 5 wt.-% titanium dioxide and/or other opacifier.
The glass preferably consists primarily of the oxides o~
sodium, potassium, calcium, barium, boron, aluminium and/or silicon with a small proportion of titanium, the TiO2 optionally present being melted in the glass and functioning, not as an opacifier, but as a germination agent for the crystallization of leucite. Oxides of cerium and optionally of P and Zr may also be contained in the glass. The glass preferably contains as main constituents SiO2, Al203 and K2O, preferably in respective amounts of 40 to 70 wt.-%, 10 to 25 wt.-% and 8 to 28 wt.-%. Other glasses can also be used.
To manufacture the glass, the oxide mixture is melted, quenched in water and worked up in a manner known per se into a fine glass powder.
In detail, for example, the molten oxide mixture is quenched in water and ground up in a ball mill. The glass powder is then .
, 207~9~
tempered at ca. 900 degrees C, sintering together to form a block which is quenched in water while still glowing. A granulate forms which is ground up in an alcohol/water mixture in the ball mill. The result is a slip which is dried and then passed through a screen.
This glass powder is mixed with zirconium dioxide. The mixture is manufactured in the ratio of, at most, 9 parts glass per part zirconium dioxide. Preferred mixture ratios lie between 4:1 and 1:1.5.
To manufacture the ready-to-use opaquer, the powder mixture is mixed with a liquid. For example, the powder can be admixed with distilled water on a ceramic plate to produce an opaquer.
However, other liquids such as glycerin or glycol can also be used for the admixing process.
In a particularly preferred embodiment, 3 parts by weight glass are mixed with 2 parts by weight zirconium dioxide and homogenized with a further 2 parts by weight glycerin on a triple roll mill.
For application as priming material, the resultant paste is deposited on a crown with a brush and stoved at temperatures of between 800 and 1000 degrees C. The result is a covering white layer which displays no discolorations even at the metal edges, is distinguished by a high covering power and offers good adhesion between metal and ceramic. The crown is then faced with ceramic by conventional methods.
Colour pigments can optionally be added to the powder mixture in order to endow the stoved opaquer with a tooth colour-like colour. The colouring substances can also be added during homogenization, however.
:. .
2~7~9~
It is also possible to add other known ceramic powders to the glass powder in order to vary the coefficient of thermal expansion (CTE). The CTE value is known to be an important parameter in metal ceramic facing work and must suit the alloy which is to be faced.
The zirconium dioxide particles have an average particle size of 1 ~m + 0.2. The zirconium dioxide particles also have a specific surface of about 1 to 20 mZ/g and a purity o 99% +/- 1.
The following examples explain the invention.
Example ~
Manufacture of a melt A with high CTE:
glass of the following composition was melted in the usual way:
5.95 wt.-% Na20 13.86 wt.-% K20 3.48 wt.-% CaO
1.64 wt.-% BaO
1.36 wt.-% B203 16.09 wt.-% Al203 0.37 wt.-% TiO2 57.25 wt.-% SiO2.
.
This glass was quenched in water and ground up in a ball mill until the average granulation was ca. 80 to lOO um.
The glass powder was then tempered for an hour at 900 degrees C, sintering together to produce a block which was quenched in water while still glowing. The resultant granulate was ground up to an average granulation of below 20 ~ in an alcohol/ water mixture (1:1) in the ball mill. The grinding time depends on the size and type of the ball mill.
6 ~ ~
For example 200 g coarse glass powder 800 g porcelain balls with 9 mm diameter 100 g distilled water 100 g alcohol were allowed to run on rolls for 8 hours in a 1-1 porcelain drum.
The resulting slip was dried at 100 degrees C and passed through a 60-um screen to avoid agglutinated lumps.
60 g of this melt were mixed with 40 g zirconium dioxide with an average granulation of 1 ~ which is marketed by Magnesium Elektron under the trade mark "Zirkonoxid SC15".
This mixture was blended with 40 g glycerin to form a paste and homogenized on a salve triple roll. The homogenized paste was painted onto a nickel/chromium alloy with a brush and then stoved at 960 degrees C with a 2-minute holding time. The result was a covering white matt layer of very good adhesive~
strength which could then be overlaid with ceramic dental materials. The coating also displayed no discolorations even at the metal edges.
Samples were burned in order to check the strength and the CTE.
The following values were measured:
Bending strength 143 +/- 11 N/mmZ
Flexural modulus 73000 +/- 6000 N/mm CTE 100 - 500 degrees C 14.4 x 10 /K
Example 2 Using the melt A referred to in Example 1, a paste was manufactured according to the following formulation and homogenized as in Example 1:
g melt A
g zirconium dioxide SC15 g ceramic colour 23264 *
.. ~ , ~.
.. . .
~7~
g ceramic colour 26077 **.
0.5 g ceramic colour 14-R-481 ***
2 g SiO2, BET surface 200 ~/- 25 (Aerosil 200 [R] Degussa) g glycerin.
- * orange-yellow, based on Zr and V oxide (Degussa) ** yellow-brown, based on Zr, Cr, Fe, Al oxide (Degussa) *** dark brown, based on Si, Co, Ni, Zn, Fe, Cr, Mn oxide (Ferro) A creamy paste was obtained which could be spread well with the brush. After burning on a nickel/chromium alloy at 960 degrees C a covering, tooth-coloured layer was obtained the colour of 15 which is the same all over.
Bending strength 161 +/- 23 N/mm Flexural modulus 67000 ~/- 2000 N/mm CTE 100 - 500 degrees C 15 x 10 /K.
Example 3 An Ivoclar ceramic powder, usual for metal ceramics, for melt configuration with a CTE 100-600 degrees C of 13.5 x 106/K, a 25 glass point of 585 degrees C and a dilatometer softening point of 600 degrees C was ground wet to an average grain size o < 20 r, dried and deagglomerated by screening as described in Example 1. This powder was named GM-DS.
3~ The following mixture was manufactured:
35 g melt A from Example 1 25 g GM-DS
21 g zirconium dioxide SC15 35 14 g ceramic colour 23264 g ceramic colour 26077 , `
~1~7~
g The mixture was intimately m}xed in a ball mill. It was processed by mixing 1 g of this mixture with water and depositing on a nickel/chromium alloy with a brush. The appearance was the same as in Example 2, except that a glossier surface was obtained. Testing of the CTE value between 100 and 500 degrees C gave a result of 14.5 x 106/K, which shows that the CTE value can be varied by adding other ceramic materials.
Example 4 (comparative examPle with ~L~a~L~
In order to compare the covering power with other opacifiers, the following mixture was manufactured and processed as described in Example 1:
60 g melt A from Example 1 25 g annealed tin dioxide 17 g ceramic colour 23264 11 g ceramic colour 26077 45 g glycerin Processing of this mixture produced an inadequately covering layer in which the black oxides of the nickel/chromium alloy falsified the colour. Because of the high tin dioxide content, the burning temperature of this mixture was already at 1100 degrees C, which is at the upper limit for the stoving alloys usual in dental engineering. The mixture also became discoloured when stored in the light.
Example 5 (comparison with various opacifiers!
In order to compare the covering power wi~h titanium dioxide, a special glass had to be melted and worked up as indicated in Example 1 for melt A. The melt~ named melt B, had the following composition:
. . .
: .
2~7~
7.12 g Na20 11.82 g K20 3.2 g CaO
1.51 g BaO
1.25 g B203 14.5 g A1203 0.34 g TiO2 59.35 g SiO2 10 The following mixture was manufactured as in Example 1:
70 g melt B
30 g opacifier 15 40 g glycerin The following table contains the opacifiers used and the test results for the processing on nickel/chromium alloys:
Opacifier Processing Covering Discoloration consistency power upon stoving Titanium 25 diOxide AD good very good dark grey Titanium dioxide R-KB-2 good very good grey/brown Titanium dioxide RN-56 good very good grey/brown Precipitated 30 tin oxide pasty inadequate white Zirconium ~nn ~ dioxide > 1 ~¢ liquid inadequate white ffh~ Zirconium silicate pasty inadequate white The discolorations in the case of the samples with titan.ium dioxide were uneven and clearly more marked towards the mei~.al edge, so that this discoloration was unacceptable after stoving.
2~7~
~L "~
The samples with tin oxide, zirconium dioxide > 1 ~ and zirconium silicate had an inadequate co~ering power and were likewise not acceptable.
. . . .
.
Claims (22)
1. A method for the manufacture of a priming material for the overlaying or coating of a metallic tooth crown or bridge by using a mixture and moistening the same with a liquid, wherein the mixture contains a matrix forming glass powder and as opacifier 10 to 60 wt.-% ZrO2, the average particle size of the ZrO2 is 1 µm ? 0.2 and the zirconium dioxide particles have a specific surface of about 1 to 20 m2/g.
2. The method according to claim 1, characterized in that the glass powder comprises the oxides of Na, K, Ca, Ba, B, Al and Si.
3. The method according to claim 2, characterized in that the glass powder contains as main constituents - 40 to 70 wt.-% SiO2, - 10 to 25 wt.-% A12O3 and - 8 to 20 wt.-% K2O.
4. The method according to claim 2, characterized in that the glass powder also contains oxides of Ce and optionally of P and Zr.
5. The method according to claim 1, characterized in that the mixture also contains, at most, 5 wt.-% TiO2 and/or other opacifiers.
6. The method according to claim 1, characterized in that the mixture contains 20 to 45 wt.-% ZrO2.
7. The method according to claim 1, characterized in that the zirconium dioxide particles have a purity of 99%
+/- 1.
+/- 1.
8. The method according to claim 1, characterized in that the mixture also contains colour pigments and/or usual additives.
9. The method according to claim 1, characterized in that the weight ratio of glass powder to zirconium dioxide opacifier lies in the range from 9:1 to 1:1.5.
10. The method according to claim 1, characterized in that the liquid is distilled water or glycerin.
11. The method according to claim 10 characterized in that the mixture contains 3 parts by weight glass with 2 parts by weight zirconium dioxide and 2 parts by weight glycerin in homogenized form.
12. A priming material for the overlaying or coating of a metallic tooth crown or bridge comprising:
a matrix forming glass powder; an opacifier consisting of between 10 and 60wt.-% ZrO2, the average particle size of the ZrO2 being 1 µm ? 0.2 and the zirconium dioxide particles having a specific surface of about 1 to 20 m2/g; and a liquid.
a matrix forming glass powder; an opacifier consisting of between 10 and 60wt.-% ZrO2, the average particle size of the ZrO2 being 1 µm ? 0.2 and the zirconium dioxide particles having a specific surface of about 1 to 20 m2/g; and a liquid.
13. A priming material according to claim 12, wherein the glass powder comprises the oxides of Na, K, Ca, Ba, B, Al and Si.
14. A priming material according to claim 13, wherein the glass powder contains as main constituents - 40 to 70 wt.-% SiO2, - 10 to 25 wt.-% A12O3 and - 8 to 20 wt.-% K2O.
15. A priming material according to claim 13, wherein the glass powder also contains oxides of Ce and optionally of P and Zr.
16. A priming material according to claim 12, and further comprising, at most, 5 wt.-% TiO2 and/or other opacifiers.
17. A priming material accordiny to claim 12, wherein the opacifier is between 20 and 45 wt.-% ZrO2.
18. A priming material according to claim 12, wherein the zirconium dioxide particles have a purity of 99% +/- 1.
19. A priming material according to claim 12, and further comprising colour pigments and/or usual additives.
20. A priming material according to claim 12, wherein the weight ratio of glass powder to zirconium dioxide opacifier lies in the range from 9:1 to 1:1.5.
21. A priming material according to claim 12, wherein the liquid is distilled water or glycerin.
22. A priming material according to claim 21, wherein the priming material contains 3 parts by weight glass with 2 parts by weight zirconium dioxide and 2 parts by weight glycerin in homogenized form.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP4119483.7 | 1991-06-13 | ||
| DE4119483A DE4119483A1 (en) | 1991-06-13 | 1991-06-13 | MIXTURE AND USE OF THE SAME |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2070691A1 true CA2070691A1 (en) | 1992-12-14 |
Family
ID=6433846
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002070691A Abandoned CA2070691A1 (en) | 1991-06-13 | 1992-06-08 | Method for the manufacture of a priming material |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0518454B1 (en) |
| AT (1) | ATE126049T1 (en) |
| AU (1) | AU650338B2 (en) |
| CA (1) | CA2070691A1 (en) |
| DE (2) | DE4119483A1 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5713994A (en) * | 1996-06-10 | 1998-02-03 | Ceramco Inc. | Low-fusing temperature porcelain, compositions, prostheses, methods and kits |
| US5849068A (en) * | 1993-06-24 | 1998-12-15 | Dentsply G.M.B.H. | Dental prosthesis |
| US6428614B1 (en) | 1999-07-02 | 2002-08-06 | Jeneric/Pentron, Inc. | Dental porcelains |
| US6761760B2 (en) | 1999-07-02 | 2004-07-13 | Pentron Corporation | Dental porcelains |
| US9631868B2 (en) | 2013-02-19 | 2017-04-25 | Ivoclar Vivadent Ag | Dental furnace having a combined display and operating device |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0630639A1 (en) * | 1993-06-25 | 1994-12-28 | Vita Zahnfabrik H. Rauter GmbH & Co KG | Dental ceramic restoration having a multilayered structure |
| DE4423794C1 (en) * | 1994-07-01 | 1996-02-08 | Ivoclar Ag | Glass ceramic containing Zr0¶2¶, process for its production and its use |
| DE4443173C2 (en) * | 1994-12-05 | 1997-04-10 | Schott Glaswerke | Barium-free dental glass with good X-ray absorption |
| EP0747034B1 (en) * | 1995-06-08 | 2001-08-16 | Vita Zahnfabrik H. Rauter GmbH & Co. KG | Powder mixture for the preparation of a paste of opaque material |
| DE10022559B4 (en) * | 2000-05-10 | 2004-07-22 | Petroll, Claudia | Means for the adhesive bond of dental ceramics to metal substrates |
| DE102004010138B4 (en) * | 2004-02-27 | 2006-04-06 | Heraeus Kulzer Gmbh | Reinforced, pressable ceramic compositions for dental purposes |
| DE102013007894A1 (en) | 2013-05-08 | 2014-11-13 | Heraeus Kulzer Gmbh | Durable dental material with improved transparent properties |
| EP3659574A1 (en) * | 2018-11-29 | 2020-06-03 | Ivoclar Vivadent AG | Method for producing a zircon oxide blank |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB897686A (en) * | 1961-01-06 | 1962-05-30 | Arthur Abbey | Improvements in and relating to ceramic artificial teeth and a process for the preparation thereof |
| GB1105111A (en) * | 1963-10-08 | 1968-03-06 | Nat Res Dev | Improvements in dental materials |
| GB1123410A (en) * | 1964-11-20 | 1968-08-14 | Du Pont | Opacifying pigment composition |
| GB1464364A (en) * | 1974-06-07 | 1977-02-09 | Secr Social Service Brit | Dental constructions |
| FR2454796A1 (en) * | 1979-04-24 | 1980-11-21 | Peter Paul | PROCESS FOR IMPROVING THE MECHANICAL STRENGTH OF DENTAL PORCELAIN |
| US4879136A (en) * | 1987-02-24 | 1989-11-07 | Dentsply G.M.B.H. | Method of applying opaque dental ceramic material to a metal structure |
| US4806383A (en) * | 1987-02-24 | 1989-02-21 | Dentsply Gmbh | Method of applying opaque dental cermic material to a metal structure |
| US4960733A (en) * | 1987-02-28 | 1990-10-02 | Hoya Corporation | Inorganic biomaterial and process for producing the same |
| EP0328772A3 (en) * | 1988-02-17 | 1990-08-29 | Dentsply International, Inc. | Dental ceramic material and methods |
| SE465571B (en) * | 1989-04-10 | 1991-09-30 | Stiftelsen Ct Foer Dentaltekni | SET TO MAKE A COMPOSITIVE CERAMIC MATERIAL WITH BIOACTIVE PROPERTIES |
| SE467562B (en) * | 1990-12-11 | 1992-08-10 | Stiftelsen Ct Foer Dentaltekni | DENTAL FILLING MATERIAL CONTAINING PHYTIC ACID |
-
1991
- 1991-06-13 DE DE4119483A patent/DE4119483A1/en active Granted
-
1992
- 1992-05-31 EP EP92250136A patent/EP0518454B1/en not_active Expired - Lifetime
- 1992-05-31 DE DE59203186T patent/DE59203186D1/en not_active Expired - Lifetime
- 1992-05-31 AT AT92250136T patent/ATE126049T1/en not_active IP Right Cessation
- 1992-06-03 AU AU17395/92A patent/AU650338B2/en not_active Ceased
- 1992-06-08 CA CA002070691A patent/CA2070691A1/en not_active Abandoned
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5849068A (en) * | 1993-06-24 | 1998-12-15 | Dentsply G.M.B.H. | Dental prosthesis |
| US6126732A (en) | 1993-06-24 | 2000-10-03 | Dentsply Detrey Gmbh | Dental prosthesis |
| US5713994A (en) * | 1996-06-10 | 1998-02-03 | Ceramco Inc. | Low-fusing temperature porcelain, compositions, prostheses, methods and kits |
| US6428614B1 (en) | 1999-07-02 | 2002-08-06 | Jeneric/Pentron, Inc. | Dental porcelains |
| US6761760B2 (en) | 1999-07-02 | 2004-07-13 | Pentron Corporation | Dental porcelains |
| US9631868B2 (en) | 2013-02-19 | 2017-04-25 | Ivoclar Vivadent Ag | Dental furnace having a combined display and operating device |
Also Published As
| Publication number | Publication date |
|---|---|
| EP0518454A3 (en) | 1993-01-20 |
| DE4119483C2 (en) | 1993-06-09 |
| EP0518454B1 (en) | 1995-08-09 |
| EP0518454A2 (en) | 1992-12-16 |
| AU1739592A (en) | 1992-12-17 |
| ATE126049T1 (en) | 1995-08-15 |
| DE59203186D1 (en) | 1995-09-14 |
| DE4119483A1 (en) | 1992-12-24 |
| AU650338B2 (en) | 1994-06-16 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued |