JPS62108750A - Mica-iolite base glass ceramic material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a mica-iolite glass-ceramic material, which is suitable for use in the structure of machine fittings and biocompatible materials in the medical sector based on its properties in a broad sense. It can be used as This applies, inter alia, to tooth restorations, in particular inlays, crowns, tooth constructions, bridges and synthetic resin dentures, metal cores or external coverings for covering natural teeth in the color of natural teeth. Tooth enamel for treatment with fixed implants, as bonded brackets and bonded bone substitutes, in various dental applications such as for dental surgery, and also in jaw orthopedics/orthodontics, among others. As a quality fixation point, or as an implant material for head/neck surgery, or even for the ear, nose, sinuses,
It can be used as a permanent hard tissue substitute in skull base and tracheal surgery.

[Prior Art] Glass-ceramic materials containing iolite or mica as the main crystalline phase are known.

For example, West German Patent Application No. 2.915.570
The iolite-based glass-ceramic material mentioned in the publication has an iolite crystal with a linear thermal expansion coefficient of, for example, 12.
It has very good thermal properties due to its low x 10-7 (°K)-1. Also, for example, U.S. Patent No. 4.304
．． 60:] and West German Patent No. 3,130.97
In the iolite glass-ceramic material according to No. 7, a material with a considerably high strength of 250-:]00 MPa can be developed, and at that time, the fracture toughness expressed in 1c value reaches up to 2.5 MPa rn''2. Advantageous strength zones can be created in the glass-ceramic material.

However, such glass-ceramic materials containing iolite as the main crystalline phase cannot be machined, in other words they cannot be formed with conventional hard metal tools.

Some glass-ceramic materials with advantageous processability are disclosed, for example, in German Patent Application No. 2,133,652, in German Patent Application No. 2,224,990 and in German Economic Patent No. 113,885. mica-based glass-ceramic materials are known.

The platelet-like mica in the mica-based glass-ceramic material is easily cleaved, and because of the fragile cellular structure of the mica crystals, this material can be processed well with hard metal tools. West German Patent Publication No. 2.13 mentioned above
No. 3,652, West German Patent Publication No. 2,224,9
Publication No. 90 and East German Economic Patent No. 113,88
Glass-ceramic materials containing platelet-shaped mica according to No. Substantially improved machinability compared to conventional materials (e.g., fluorophores) has been achieved with the development of a new type of glassaceous ceramic material containing curved fluorophlogobite crystals. East German Economic Patent Nos. 153 and 108 and later publications such as Glass Technology 2
Such glass-ceramic materials, described in various publications such as 4 (+983) 318, contain an optimal concentration of curved fluorophlogobite crystals with a size of 25-100 μm in the remaining glass matrix. It shows a structure in which the crystals are embedded in and in contact with each other, thereby creating the best prerequisites for optimal processability. East German Economic Patent No. 153.108
Although the material disclosed in the above publication is the best mica-based glass-ceramic material in terms of workability, it is difficult to use machinable glass-ceramic materials as structural materials, especially for medical applications. For this reason, the values of fracture toughness, hardness, compressive strength, abrasion resistance, and coefficient of linear thermal expansion of the material are still insufficient.

Materials used in the dental field for inlays, crowns, dental constructions and bridges include, among others, various noble metals and their alloys, sintered ceramic materials and various organic polymeric materials. However, these materials have significant drawbacks. Precious metals are expensive, have high thermal conductivity, and do not always have aesthetically pleasing colors. Sintered ceramic materials cannot be processed with conventional hard metal tools and exhibit various disadvantages during processing due to the shrinkage that occurs.

Perforated polymeric materials have particularly unsatisfactory mechanical strength.

U.S. Pat. No. 4,4:11.420 and European Patent No. 22,655 and U.S. Pat. No. 4,51
Publication No. 5,634 and West German Patent Publication No. 3,435
The glass-ceramic materials described in No. 348 also have woody disadvantages for use in dental applications, since their properties are not optimally matched to the properties of tooth enamel. This is true, for example, in U.S. Pat.
Publication No. 431,420 and European Patent No. 22
This also applies to the linear thermal expansion coefficient of the tetrasilicate mica glass-ceramic material described in , No. 655, published in (The Intern, J.

of Periodontics and Re
5tauraL, Su, (84) 36) 72X 10-'('K)-' and is thus significantly lower than the value for enamel of 1+4X 10-'(''K)-1. Such significant differences even at very small temperature differences can cause uncontrollable stresses between the tooth and its glass-ceramic material, which can lead to fracture of the material or the formation of cracks at the edges. Moreover, the +lb C strength of these glass-ceramic materials is of the order of 50-55 MPa, which is insufficient for a wide variety of applications in the dental sector, especially as thin-walled moldings.

Another drawback of these tetrasilicate mica glass-ceramic materials is apparently based on their 1lHi problem.
This means that it is not possible to create a bonding material with a substrate of high strength materials such as corundum or various metals.

For glass-ceramic materials containing fluorophlogobite, such as those described in East German Economic Patent No. 11:], 885 and East German Economic Patent No. 153,108, these have very good processability. It is known to have a variety of properties that allow it to be used, for example, in the construction of machines and appliances. However, when these materials are used for various applications in the dental sector, there are significant differences due to their properties, e.g. thermal properties, hardness, etc., which are not optimally adapted to the tooth enamel. Shortcomings will appear.

In addition to various synthetic resins, sintered ceramic materials are used as general exterior materials. The outer shell is made of sintered ceramic material, and the outer shell is made of synthetic resin material.
ent (1L] 5 years), Pa1adon (19
37/38) and Pa1apont (194
0 years) is the so-called 5 chroed in the dental treatment field.
It was first produced industrially when it was introduced as a hollow tooth (f; aviden) by Mr. Er. They have been used as outer shells for certain synthetic teeth from the various synthetic resin materials mentioned above with the purpose of improving their still insufficient wear resistance.

In the past, certain individually made outer shells were also known from sintered ceramic materials, in which case 5 Chroeder
(1932) promoted this cladding technique with the introduction of ceramic materials for tooth B. It should be noted that in the period from 1952 to 1969, as a reaction to the long-term unsatisfactory results of synthetic resin shells, shells of sintered ceramic material were preferred for crowns; Certain sintered ceramic materials were primarily used, such as full bone dentures and platinum long axis dentures. The system introduced at that time of tooth crowns sheathed with mineral materials was based on the putamen of a certain final shape obtained by carving from the tooth of the above-mentioned faithful body (E.

Reumu Lh and E, 8rnold; “Faceted Crown of Rostsk”: Dtsch, Stoma
t, 13 (+963) 391-:J98, E
, 8rmbrecM and A, Gerber;
“Schcherin faceted dental crown”: Zahntec
hnik (Berlin) mutual (1964) 93-103
).

With the development and introduction of so-called metal-ceramic materials into the market, there has been a decline in tooth-shell technology in countries where such metal-ceramic materials are readily available, while in places where such metal-ceramic materials are not readily available, the work of dental technicians has improved. The industrial production of external dental membranes of sintered ceramic materials was encouraged in order to alleviate the problems (It, Richt, cr; "Keraset, ceramic material dental membranes": ZahnLechni
k (Berli:/) +7 (1976) 313-
:+16). The availability of divine composite materials, together with the introduction of various bonding techniques in clinical and dental technology, has led to the introduction of new types of sintered ceramic materials onto the market, which are primarily used for the "facade" of anterior teeth. used by dentists themselves for ``repairs'' (J, R, Calamia; ``Etched bauselin overlays, current state of the art'': quint, I
nt, 16 (1985) 5-12).

The outer tooth membrane of sintered ceramic material is 1.5 to 2
It is only possible to make a film with a minimum thickness of +nm or less.

They are therefore not suitable for the cortical layer, which is made of ceramic material, of the connecting tooth membrane.

One of the hydroxylapatite-based glass-ceramic materials has been described by S. Ilbobo and T. Iwat. a, which uses a casting technique to coat the dental membrane for the outer covering of the visible surfaces of the teeth. (S, Hobo and T, Iwata)
: "Castable apatite-based ceramic material as a new biocompatible repair material, 1. Theoretical considerations": Q
uilInL 16 (1985) 135-141)
. This glass-ceramic material is especially designed for individual finishing techniques and, like sintered ceramic materials, only allows the production of tooth membranes with relatively large wall thicknesses and is suitable for industrial manufacturing techniques. , or layers of synthetic resins or adhesives, for example to provide modified colors.

The aforementioned glass-ceramic material (U.S. Pat. No. 4.431
, 420, European Patent No. 22,655, U.S. Patent No. 4,515,634, West German Patent Publication No. 3,435,348, East German Economic Patent No. 113,885 and East German Economic Patent No. 153.108) is not known for use in exterior shells, and it was expected that the various disadvantages mentioned above would have a negative effect on such use.

Metals, synthetic resins, and sintered ceramic materials are conventionally described as materials for adhesive brackets. At present, certain tooth adjustment elements are mainly made of metal due to their good mechanical stability and their adjustment curved members (Regulier).
ungsbogen) due to its low friction in the kerf. The preparation of surfaces for various orthodontic adhesives on the base surfaces of certain tooth adjustment elements from these metals involves considerable effort and requires complex technical methods in order to obtain sufficient bonding strength. 2,618,952, for example, or the production of a base with perforations in the periphery, as described, for example, in DE 2,910,070. photoetched spherical recess,
It requires the use of a retaining net base or cutting out grooves in the model. By using such complicated techniques, metal adhesive brackets can be used with up to 12. :l
Bond strengths up to hlPa can be achieved (P, D
iedrich, B., Dickmeiss: Fo
rtschr.

1eferorthop, 44 (1983) 2
98-310). The problem with the use of metal adhesive brackets is that they exhibit various corrosion phenomena and lead to permanent discoloration of the tooth enamel, which according to Appert et al.
ortschr.

1eferorthop, 45 (1984) 2
71-283) should be attributed to traces of chromium and iron. Although this aesthetically unfavorable effect of metallic tooth conditioning elements can be improved by a natural tooth-colored synthetic resin outer coating according to U.S. Pat. No. 4,527,975, in this case In addition to the significantly higher material costs and longer time required to apply and produce a suitable outer covering, the risk of caries development for the patient is also substantially increased.

Brackets made of synthetic resin, such as those according to British Patent No. 1,506,772, for example, exhibit an essentially aesthetically pleasing effect compared to metal brackets, but this is due to the effects of food and other luxury items. It may be significantly reduced due to discoloration of the synthetic resin material. In the case of brackets made of synthetic resin, it is also a disadvantage that they have a low mechanical strength, which is
According to Ch.
op, 42 (1981) 195-208)
, high J9 friction also appears in the kerf. These drawbacks are also only insufficiently eliminated by fitting metal inserts into the kerfs, as shown, for example, in German Patent No. 2,742,896.

Ceramic materials such as those described in DE 2,913,509 and US Pat. No. 4,219,617, among others At20. Brackets made of aluminum have both an aesthetically pleasing effect and good mechanical strength, and are therefore superior to brackets made of metal or synthetic resin. However, in the case of brackets made of these ceramic materials, manufacturing is complicated and problematic, especially because uncontrolled shrinkage occurs during the sintering process, which necessarily requires mechanical post-processing. However, this can only be achieved using diamond tools. Similarly,
The individual matching of the base of the ceramic bracket to the tooth profile, which is required in certain cases, is only possible with great difficulty, since the ceramic material has its own structure and structure. This is because it has very poor processability due to the various crystal phases contained in it. Furthermore, in the case of adhesive brackets made of ceramic materials, in order to obtain sufficient bonding force, it is necessary to provide many carved parts in the base surface of the bracket in order to allow the orthodontic adhesive to adhere well. The disadvantage is that this leads to additional effort in the production of adhesive brackets made of the ceramic material.

Al2O as a graft material in head/neck surgery,
It is known to use ceramic-based or glass-ceramic materials. These known glass-ceramic materials have the disadvantage that, due to their chemical composition, the different crystalline phases precipitated and their texture, they are difficult to process during surgery.

Furthermore, West German Patent Publication No. 3,211,211 and West German Patent Publication No. 3,211,209
A combination of bioinert and bioactive materials for auditory ossicular prosthesis is known from US Pat. A disadvantage of such technical measures is that the combined material cannot be processed intraoperatively due to its material strength and bioinert surface coating.

Moreover, the surgeon must be provided with a highly diverse and standardized assortment of different implants depending on the respective anatomical conditions. Another disadvantage of known combinations using this commonly known glass-ceramic material is that each component has a different coefficient of thermal expansion.
Among other things, this means that tissue defects may occur at the joints during sterilization. Particularly in the case of large-area implants, the different coefficients of thermal expansion of their components have a disadvantageous effect.

[Problems to be Solved by the Invention] The object of the present invention is to solve a completely new field beyond the conventionally known state of the art, particularly in various applications in the medical field, particularly in the dental field and in the field of head/neck surgery. The object is to develop glass-ceramic materials that can exhibit different properties that allow them to be used in fields of application.

In other words, the object of the present invention is to create a glass-ceramic material that can be processed well using ordinary hard metals, and at the same time has high fracture toughness, high hardness, and various properties that can be adjusted according to each application. In doing so, the special objectives of the present invention are as follows: (1) With regard to the use of the glass ceramic material in the dental field, ○ The glass ceramic material is well compatible with living organisms, and ○ Natural teeth and artificial dentistry. be able to minimize the differences in expansion coefficients that traditionally existed between the materials; be able to overcome the insufficient hardness and strength of traditionally used dental materials; ○ The very expensive precious metals and alloys used in the past can be replaced by economically preferable raw material systems through the use of new materials, and ○ The conventional glass engineering (2) Regarding the use of the glass-ceramic material in the outer shell, the glass-ceramic material can be synthesized using simple primary forming technology and shape correction technology. (3) It is possible to easily adapt and bond to resin dentures, metal cores or natural teeth, and industrial manufacturing methods can be used; (3) jaw shaping of the glass ceramic material; (4) Also for use in the field of surgery/orthodontics: the glass-ceramic material has a high retention capacity for orthodontic adhesives, and (4) also for use in the field of head/neck surgery. Regarding its utilization, the glass-ceramic material can be well processed intraoperatively by the usual instruments that can be used during surgery, thereby making the implant unique to each individual anatomy, which is very different. o A combination of the glass-ceramic material with other highly bioactive glass-ceramic materials is possible.

[Means for solving the problems] According to the present invention, the above-mentioned problems are solved as follows,
That is, the glass-ceramic material has the following composition in weight percent: SiO□43-50% to 1□03-26-30%M
gO11-15% R207-10,5% F-3,1-4,8% CI-0,01-0,6% Ga0 0.1-3%P2O50,
1-5% with the exception that R20 is 3 to 5.5% by weight of N.
a2O and 4 to 6% by weight of iolite) and contains mica as the crystalline phase in addition to 5-30% by volume of iolite, the structure of which is 10-10% in the glass matrix phase. Relatively large mica crystals with a size of 200 μm are embedded, and the diameter is 0.5-5 μm.
The solution is to have the characteristic that iolite crystals with a size of .mu.m are distributed in a distributed arrangement, in which case platelet mica with a size of 0.5-5 .mu.m may also be present.

This mica-iolite glass-ceramic material is made of BaO1S to improve its physical and chemical properties.
Additives rO and PbO in amounts up to 8% by weight,
And to realize any color state, Ni01Cr20
3. Coloring components such as MnO□, FeO, Fe2O3 and TiO□ can be contained in amounts up to 4% by weight.

Surprisingly, the unfavorable properties of glass-ceramic materials that contain only large bent cloud ITJ crystals as crystalline phase can be solved by intentionally doubly crystallizing the starting glass to form large bent mica crystals. This was overcome by precipitating, in addition to the crystals, small tabular mica crystals and/or a second crystalline phase representing iolite between the large curved mica crystals.

The formation of an iolite crystalline phase in this glass-ceramic material was clearly confirmed by examination by X-ray diffraction and evaluation by scanning electron microscopy.

However, such a doubly controlled crystallization is possible when the well-known Sin□-^1zOi-MgO-Na20-
In the F- system, each of these components, namely SiO□,
Al2O3, MgO5N a 2 (1, K2O and F- are chosen within a narrow composition range according to the invention, and the glass-ceramic material is at the same time 0.0
1-0.6 weight% of 61-10.1-3 @ amount% of Ca
This is achieved only when containing O and 0.1-5% by weight of P2O. Such a relatively narrow compositional range according to the invention is a fundamental prerequisite for being able to proceed with the necessary microphase formation process in a deliberately doubly controlled crystallization in the starting glass. be. In this case, it is characteristic that the starting glass consists of a t1m-like glass phase and a glassy matrix phase. This was clearly confirmed by electron micrographs. The liquid lamellar glass phase is a silicate phase rich in M g 2 +, Na'', K'' and A13+, and the glass matrix phase is 5 in.
It is rich in 2. From the droplet-like glass matrix phase, the aforementioned curved mica crystals are formed during the heat treatment process, and these crystals are, as is known, particularly richer in A13+ than the tabular mica crystals (Iloeland, Vogel et al.: G
lass Technology 24 (1983)
318). Therefore, as crystallization progresses further, not only A13+ but also Mg2'', F-, and F- are present in the remaining glass.
ions and (of course) 5in2 appear, whereby firstly the still remaining straight plate mica and then the iolite when the Na+ and r ion concentrations among others within its glassy phase are further reduced. Forced crystallization occurs. Therefore, the diffusion process which is crucial for crystallization can be precisely controlled at different stages of the heat treatment, and the progress of the formation process of different crystal phases can be controlled by warping; It is possible to determine the amount ratio of

Components lag, SrO and pbo up to 8% by weight, and for example Ni01Cr20. , MnO2, Fc
Additional desired coloration, different opacity or even fluorescence, etc. can be achieved in the material by adding coloring components such as 01Fe203, TiO2, etc. up to 4% individually or as a mixture. can give.

The starting glass can be produced by shaping it into the respective object by forming methods known in glass engineering, such as molding, pressing, centrifugation or glass blowing. The moldings so made can then be cooled to room temperature or directly
The glass-ceramic material according to the invention is converted within a temperature range of 0°C.

When the starting glass is crystallized in situ, it is advantageous to embed the molding in or to enclose it in a mold, for example a metallic or ceramic material. This makes it possible to produce objects with even extremely complex external shapes without even minimal deformation.

[Function] The glass-ceramic material according to the invention thus obtained has excellent machinability, a fracture toughness of up to 2.0 MPa m"2, a value of II Vo, o7 of 1,000
hardness up to 450 N/mm2, compressive strength up to 75
It has a special combination of properties: a coefficient of linear thermal expansion of -125x10-3 and good chemical stability as well as high abrasion resistance.

A very significant inventive step in this combination of properties compared to the state of the art previously known is that large curved mica crystals and platelet-like mica crystals and/or small iolite crystals in the glass-ceramic material according to the invention It is brought about by simultaneous precipitation. In this case, micro-stress (Mikrospann
The formation of ungen) has a decisive influence on the desired changes in various properties and the resulting new fields of application, especially in the medical field.

In addition to offering excellent processability, this mica-iolitic glass-ceramic material is surprisingly useful in dentistry with respect to the formation of special properties such as high strength, adjustable expansion coefficient, biocompatibility, etc. It has been found that it can be used in the area. This surprising application advantage results from better mechanical, thermal and processing properties as well as new physical and chemical properties compared to known biomaterials or known mica-containing glass-ceramic materials. This is based on the fact that it is created in the mica-iolite glass-ceramic material.

Initially, good chemical properties such as the hydrolytic stability of mica-containing glass-ceramic materials were known. However, it has been established for the products according to the invention that these glass-ceramic materials are biocompatible in the biological environment, for example in the human oral cavity. The surprising new physical properties of this mica-iolite glass-ceramic material include, for example, +25
a coefficient of linear thermal expansion that can be varied up to 1;
The mechanical strength and hardness, the abrasiveness of these materials, and the processability of the starting glasses for the production of ceramic materials, which can extend to the process of ceramization and the possibility of combination with high-strength materials.

According to the invention, the above-mentioned mica-iolitic glass-ceramic materials can be used in any desired form in the dental field, inter alia in inlays, crowns, architectural structures and bridges. However, in order to maintain optimum mechanical properties for these applications, a minimum wall thickness of 0.5 + nm or more is advantageous.

For example, the enamel of a natural tooth has a coefficient of linear thermal expansion of 1 x to -1. Mica according to the invention
Iolite-based glass-ceramic materials have a hitherto unknown texture, i.e., large, curved fluorophlogovite crystals and platelet-like fluorophrogrogite and/or iolite crystals are strongly reticulated with each other. It consists of things. These materials can therefore be directly matched to the coefficient of thermal expansion of natural teeth and, according to the invention, can be used for tooth restorations, for example as inlays, crowns, various dental constructions and bridges. with such an expansion coefficient as possible. Therefore, a wood-based inventive step has been achieved compared to the prior art, which avoids edge crack formation and uncontrolled stress between the biomaterial and the natural tooth. , since a long shelf life is achieved as a dental material in the lateral tooth region.

Variability in the adjustment of the expansion coefficient can also be achieved at the same time, e.g.
This is also a prerequisite for the combination of this glass-ceramic material with a high-strength material, such as a tooth building structure or a bridge structure made of a 2O3-based glass-ceramic material and a mica-iorite-based glass-ceramic material.

Very good strength and hardness properties are known for mica-based glass-ceramic materials. For use in the dental field, such as inlays, crowns, persimmon tooth building structures, and bridges, it is necessary to obtain optimal values for many mechanical properties compared to natural tooth enamel. There is. In the present invention, it has surprisingly been found that the wear behavior of mica-iolite glass-ceramic materials is similar to that of natural tooth enamel. At the same time, this material has a hardness (11■.

. 7 values) flexural failure strength greater than 300-800.80 MPs, compressive strength up to 450 N/mm2 and roughness to a depth of 0.15 μI, and e.g. TG
They have very good chemical stability corresponding to hydrolysis resistance class 1 or 2 according to L10849 or RGW-Standard 1569, and these materials can at the same time be machined very well and therefore later The use of the glass-ceramic material according to the invention as a tooth restoration product is now possible as illustrated by the examples. Additionally, U.S. Patent No. 4,431,420
Even compared to the glass-ceramic material containing tetrasilicate mica of the publication, a substantial inventive step has been achieved as measured with respect to flexural breaking strength, since this material only has a minimum value of about 50 MPa. Because it destroys it.

The inventive step achieved when using the mica-iolitic glass-ceramic material according to the invention in the dental field compared to precious metals is quite obvious. First of all, a substantially improved aesthetic effect is already achieved due to the appearance of the glass-ceramic material, which is closer to a natural tooth than, for example, a crown made of precious metals. However, the greatest effect is achieved in terms of economy due to its inherently cheap raw materials. At the same time, the main properties of this glass-ceramic material are essentially closer to those of natural tooth enamel than those of metals (e.g. thermal conductivity, expansion coefficient, abrasion resistance, mechanical properties). etc.), and unlike the known manufacturing methods of sintered ceramic materials, inlays, VII crowns, built-up structures, bridges, etc. made of mica-iolite glass-ceramic materials are manufactured using primary forming methods and corrective forming methods known in glass engineering. It is also particularly advantageous that it can be produced by methods such as pressing, centrifugation, molding, etc. According to the respective requirements, i.e. the respective anatomical conditions, e.g. inlays,
Dental crowns or structures, bridges, etc. can be made in any desired shape. In detail, the manufacturing method comprises melting a starting glass in the form of a glass sinter or compact material at 1450-1530°C and a molten glass viscosity of 10' to 10'' Pas.
At a temperature of about 1250-1350°C, corresponding to
Prepared in advance according to the desired tooth adjustment and heated to 500-1,000℃.
This consists of pouring it into a matsufuru that has been preheated to a temperature of . This material is an implantable material (Ein-be) commonly used in dental laboratories for the casting of prosthetic prosthesis prototypes, usually made of chromium/cobalt/molybdenum alloys, chromium/nickel alloys, or steel. %, mas
se). The casting groove of this Matsuful is 10 m.
m and its diameter must be at least 62 m.
It should be greater than or equal to -3 ++on. For good degassing, degassing grooves can preferably be provided together, however this is generally not necessary. During casting, the complete filling of the glass into the prefabricated moldings for producing the respective shaped body is achieved by centrifugation or by applying a vacuum.

The molded body is then cooled to room temperature in a matzuru or directly in the temperature range 650-1050°C.
．． It can be transferred to the glass-ceramic material in a period of 5 to 24 hours. In both cases a one-stage heat treatment or a multi-stage heat treatment is possible. If Matsufuru is cooled to room temperature immediately after the primary forming process, after removing the glass molding, any defects that can be detected with the naked eye (such as cracks, protrusions, bubbles, etc.)
A visual inspection is possible (e.g. parts of the mold that have not been filled sufficiently) and defective products are screened out.

If the glass molded body has no defects, this is 600.
This is transferred to the glass-ceramic dental product according to the invention by heating to a temperature of -1,000 DEG C. at a rate of lOo/min. This heat treatment will hereinafter be referred to as the ceramization process. In order to ensure mold fidelity, it is advantageous to re-embed the glass molding prior to ceramification. After the ceramization process, the glass ceramic body is removed and any remaining adhering potting material is removed using conventional dental tools or alternatively by sandblasting with fine sand. By grinding or polishing, an optimally smooth and shiny outer surface with a roughness depth of up to 0.15 μm is obtained.

By the same process steps described for the production of faithful mica-iolitic glass-ceramic material compacts for the dental field, high-strength substrates such as 8T203-based sintered ceramic materials and mica-iolitic glass-ceramic materials and voids are produced. A bonding material can be produced in which the basic body is completely or partially enclosed. In this case, the basic body is already embedded in the model, for example made of wax. The formed dental moldings according to the invention, such as bridges or building structures, have a strength of 200-400 MPa.

Another positive effect is that the glass-ceramic material dental moldings according to the invention can be coated with customary ceramic coloring pigments and/or glazes. This makes it possible, for example, to carry out individual coloring.

Similar individual coloring of mica-iolitic glass-ceramic materials can also be achieved with additive components 5rO1IlaO and Pb.
up to 8% by weight of O and the coloring component Fc01Fe203,
Mn01NiO1Cr20. , and Tie□'s 4
Although this was achieved by providing a certain coloration, this surprisingly has no essential influence on the crystalline phase formation process. Another advantage of the application of mica-iolitic glass-ceramic materials to the dental field is that they can be processed by cutting and/or drilling and/or turning and/or sawing and/or grinding due to their excellent machinability. This means that the fabrication can be carried out without requiring the use of a Guimonde tool.

According to the present invention, the use of mica/glass ceramic material for general exterior use means that the exterior shell is made of a layer of glass ceramic material in the face area, and [in the first cavity side, a layer of perforated synthetic resin material or bonding material is used]. layers, both layers being bonded by a layer of adhesive agent, which has favorable processability as well as good physicochemical properties of the glass-ceramic material, aesthetically configurable properties and color resistance. This is achieved through optimal utilization of possibilities. This makes it possible to produce thin-walled outer shells, with the glass-ceramic material layer being produced by casting or pressing methods well known in glass engineering. This provides the possibility of producing the above-mentioned outer shells industrially. This individual coloring of the outer shell is achieved by a layer of natural tooth-colored glass-ceramic material as well as a layer of natural tooth-colored organic synthetic resin or bonding material.

The glass-ceramic material layer according to the invention on the part of Moetani can reduce its wall thickness to a coating layer thickness of less than 0.5 mm, which is similar to the enamel material of natural teeth and has a biocompatibility of its outer shell. It guarantees various optical properties, and allows the synthetic resin material layer or bonding material layer to be designed with a thickness of I mm or more as a member of the composite body. This makes it possible to individually adapt the industrially produced outer shell exclusively in the area of the layer of existing plastic material or bonding material, without affecting the adhesive layer. At the same time, the lining of the glass-ceramic material layer on the oral side with an organic synthetic resin or a bonding material also allows easy adaptation and bonding to the object to be covered.

Application of the adhesion promoter layer is carried out in a known manner by using organosilicon compounds, such as tetraethoxysilane. For improved adhesion, the metal press mold is advantageously formed on the oral side of the glass-ceramic material layer on the vestibular side and reinforced by subsequent post-treatment to the actual surface. A relatively enlarged surface structure contributes. Another use according to the invention of mica-iolitic glass-ceramic materials in jaw orthopedics/orthodontics, inter alia as bonded brackets and bonded bone substitutes, involves conventional methods such as casting or pressing of the starting glass. It is of great significance that the adhesive bracket and the adhesive replacement bone fragment can be shaped to a great extent even during production by applying the primary molding method.

Due to the excellent machinability of the mica-iolitic glass-ceramic material, the final finishing of the molded body thus produced can be achieved by machining with conventional hard metal tools. On the one hand, this process can be automated by producing a standardized base body and, on the other hand, can therefore be constructed in an economically advantageous manner.

Due to the excellent machinability of the mica-iolitic glass-ceramic material, the necessary individual adaptation of the base surface of the adhesive bracket to the tooth profile can also be very easily achieved, for example by grinding with grinding tools common in dental technology. Well guaranteed and West German Patent Publication No. 2,91
:1,509 and U.S. Patent No. 4,219,
This represents a substantial improvement over the ceramic material bracket described in the '617 publication.

Compared to metal brackets, which require cumbersome methods to create a micromechanical retention surface for molded dental adhesives, or also the need to create an additional retention cavity. Compared to brackets made of ceramic materials, in the case of adhesive brackets made of mica-iolitic glass-ceramic materials according to the invention, it is already possible to obtain an excellent micromechanical retention surface only by simple finishing grinding of the base surface. , thereby making it possible to reach substantially higher bond strength values than in the case of adhesive brackets made of metal or ceramic materials. Furthermore, the linear thermal expansion coefficient of the mica-iolite glass-ceramic material can be matched to the value of the linear thermal expansion coefficient of tooth enamel, thereby reducing the stresses that appear upon temperature fluctuations. This is advantageous for the bond strength between the adhesive bracket made of glass ceramic material and the tooth enamel.

Furthermore, the excellent physical and chemical properties of the mica-iolite glass-ceramic material, its good biocompatibility, and its stability in the oral environment are important for jaw orthopedics/')! 4 It has great significance for its use in orthodontics.

The natural tooth-colored appearance of this mica-iolitic glass-ceramic material, which can be further improved by coloring additives, is very pleasing to the patient from an aesthetic point of view, in contrast to synthetic resin brackets. An important point is that, for example, there is no undesirable permanent discoloration caused by food or other luxury goods. Furthermore, the bonding bracket made of glass-ceramic material according to the invention is preferred by patients due to its shape-correcting nature and because the edges of the bonding bracket made of glass-ceramic material are folded or rounded. It is superior because of its ability to be attached to the local area.

According to the present invention, the implant material used in neck/head surgery consists only of a mica-iolitic glass-ceramic material, or a highly bioactive glass-ceramic material that can be machined and the above-mentioned biocompatible cloud 1. [・Consists of a combination with an iolite-based glass-ceramic material. The highly bioactive glass-ceramic material capable of machining has in this case the following composition (expressed in weight percent) (Nishi Kuitsu Patent Publication No. 3,306,648): 5 in 219-52 yen.

Layer 2o312-23'<Mg05-15'')6 Na20/K2O3-10'4 (:ao 9-30% p2o, 4-24'4 F O, 5-7% The biocompatible mica mentioned above. The combination of an iolitic glass-ceramic material and the above-mentioned highly bioactive glass-ceramic material can therefore be made to bond firmly to each other in its softened phase on the basis of correspondingly matched coefficients of linear thermal expansion; It is clear that this is preferable because no structural defects can occur at the phase interface during temperature fluctuations.For the processing of this combination glass-ceramic material, the highly bioactive glass-ceramic material and the It is important to be able to identify the phase interface between the mica-iolitic glass-ceramic materials. This is because a small amount of the phase interface between the glass-ceramic materials to be bonded prior to heat treatment of the starting moldings is important. This is achieved by visualization by introducing colored oxides as a colored boundary layer.

The use of mica-iolitic glass-ceramic materials according to the present invention provides the advantage of low solubility;
This ensures that the shape remains constant over time. Furthermore, it induces rapid secondary encrusting cell formation in the ears, nose, paranasal sinuses and parts of the auditory ossicles.
It has a surface charge that gives rise to erepithelisierung.

Overall, the use according to the invention of the glass-ceramic material described above has the advantage that it can be processed intraoperatively using the usual instruments available during surgery.

Furthermore, the good hemocompatibility of the mica-iolitic glass-ceramic material according to the invention allows it to be used in the cardiovascular system, for example in heart pumps.

[Examples] The present invention will now be described in more detail with reference to some examples.

Table 1 lists the chemical compositions of the glass-ceramic materials according to the invention and their respective starting glasses in weight % values. Table 2 lists examples which show the relationship between the chemical composition, the heat treatment of the starting glasses, the crystalline phase composition of the glass-ceramic material according to the invention and its properties. The properties of the glass-ceramic material according to the invention can be combined, for example, with high fracture toughness and good to very good machinability with a coefficient of linear thermal expansion adjustable within a wide range, or also with high hardness and good machinability. such as combining machinability with very good chemical stability.
There are many possible combinations.

Table 1 Table 1 (Continued) Table 1 (Continued) Table 2 Table 2 (Continued) Table 2 (Continued)
It also includes advantageous applications according to the invention of iolitic glass ceramic materials for various applications in the dental field.

Furthermore, the following two selected applications, in which this mica-iolitic glass-ceramic material is used (1) as an inlay and (2) as a dental edifice, demonstrate the effectiveness of its use in accordance with the present invention. It is something.

Application example (1) To prepare an inlay made of mica/iolite glass ceramic material, a tooth cavity is first formed. Care must be taken in this case to provide mutually perpendicular cavity walls with lightly rounded corners. Formation in which the edges become thin and pointed should be avoided. Sufficient thickness ablation is desired to result in a layer thickness of at least 1.0 + nm or more in the case of inlays. The preparation of a model that reproduces the dimensions and shape of the cavity previously prepared for implantation can be carried out either directly by wax molding in the mouth or indirectly by, for example, molding and special molding. This can be done by After the final fabrication of this template, a cast shaft with a length of 5 to 10 mm and a diameter of 2 to 3 mm is installed. The implantation is carried out in the dental laboratory using implant materials such as those used for casting high melting point dental alloys. Advantageously, a vacuum/vibration apparatus such as that commonly present in dental laboratories is utilized.

After this potting material has hardened, the cast shaft is removed and
Then slowly heat the matsufuru to 500-1.000℃.
Heat to. In this case, the template material escapes through the casting groove, and a hollow space remains in the mold, which corresponds to its original shape. Starting glass 1450-1530
melts at 1250-1350°C and about 1250-1350°C
Cast into the above-mentioned Matsuful by centrifugal casting or vacuum pressure casting at a temperature of 2. The hollow spaces mentioned above are filled. The glass-ceramic material inlay produced as a result of this casting process can then be cooled to room temperature in the mold. The item is then removed from the potting material surrounding it, the potting material removed, and inspected for any defects that may be present. If this casting is free of defects, it is re-embedded in a potting material, using a potting material having the same composition as that used in the casting. Ceramization of the glass-ceramic material inlay according to the invention is carried out by heating at a rate of 10°/min to a temperature of 150°-1050° C. for 0.5-24 hours. The inlay is then removed from the potting material.

Another IIJ feature is that the casting process described in F can be carried out without intermediate removal of the casting from the embedded material.
This is followed by a ceramization process which is likewise carried out at temperatures of 650-1050°C.

The inlay is sandblasted using silica sand to remove any residual adhering potting material. The inlay is removed from the casting groove using a conventional grinder. Next, you can try applying it in your mouth. Control the adhesion P [for example, sealing around the cavity, contact points with adjacent teeth, etc.
Occlusion, correction, etc. are performed by fine particle polishing. Next, polishing is performed in the usual manner. If necessary, such as when used in visible areas, coloring pigments are coated and fired, or various additives are added in advance to match the color of natural teeth. . The inlay is then anchored within the cavity using commonly used fixation cement or using special adhesive methods.

Application example (2) -B p)・Iolite-based glass ceramic material A
In order to produce a tooth building structure in combination with a l2O3 based sintered ceramic material, the tooth is first excised and the tooth root cavity is drilled. A ready-made mandrel (WurzelsLifL) made of Cerakock material reinforced with 81□03 is fitted. This mandrel is, for example, circular in cross-section and has different thicknesses, for example 1.4 n, depending on the width of the root cavity.
It can be made with a cross section of 1.8 mm, 1.8 mm, etc., and is slightly tapered toward the tip of the tooth root. Its length must be matched by polishing to the length of the root cavity. The original structure of the tooth corresponds in its shape to the prepared tooth pattern, and the model is made by a direct method from the model material. The work steps from embedding to the ceramicization process are the same as those mentioned in Application Example (1) above.

The ceramic tooth superstructure is tried on the patient to test adhesion. In this case, attention must be paid to the peripheral sealing behavior, length and precise shaping. Surface processing is carried out using polishing tools customary in practical technology. Filling with cement is carried out in the same manner as described in the application example (1) above, by correctly filling the tooth root in the 1/3 portion of the distal end.

Next, the essence of the present invention will be explained in more detail with reference to one example regarding the use of a mica/iolite glass ceramic material for an exterior dental membrane.

FIG. 1 shows a cross section of the exterior dental membrane according to the present invention from the vestibular side to the oral cavity side.

The exterior dental membrane according to the present invention consists of a glass ceramic material layer a on the vestibular side, an adhesive layer, and a layer C of an organic synthetic resin material or a bonding material. In this case, the glass-ceramic material layer a consists of a mica-iolite glass-ceramic material having a composition according to the invention. This product is press-molded using a metal mold, ceramicized, and surface-treated. The surface treatment is carried out by sandblasting with Al2O3/corundum with a particle size of 50 .mu.m at a pressure of 2-3 bar.

Next, cleaning is performed in an ultrasonic bath using ethyl acetate. The labial or buccal surface of this vestibular glass ceramic layer has the contour of the tooth to be formed in each case. The biting end d extends in the direction of the tongue and is formed without any undercut. On the lingual surface of this vestibular glass ceramic material layer a, an adhesion promoter layer is applied by silanization. Next, a layer of synthetic resin material or bonding material c l)': Adhesive-mediated layer removal 1
- and thereby line the oral side of the glass-ceramic material layer a on the vestibular side. In this case, a layer of synthetic resin material with high wettability is first applied, and this is then supplemented with a layer of highly filled pigment-containing pasty bonding material. Both layers contain photoinitiators and are simultaneously photopolymerized.

The use of the mica-iolite glass-ceramic material in jaw orthopedics/orthodontics according to the present invention will now be described in more detail with reference to two examples.

2.3.4 and 5 show different appearances or shapes of adhesive brackets made of glass-ceramic material, the glass-ceramic material having the basic composition and properties according to the invention. have. The base of these brackets has a width e of 4.5 n+m and a width e of 2
．． orthodontics having a length f of 5-6 mm and having a curved or flat shape and achieving a bond strength of up to 18 MPa by grinding by conventional grinding means. A micromechanical retention surface for adhesives is obtained. The height i of these brackets is up to 3 mm and each wing is formed in a straight or obliquely cut shape as shown in Figures 3 and 4, with mica-iolite glass. Each corner of the adhesive bracket of ceramic material is bent or rounded. The kerf for receiving the corrector arc of this glass-ceramic material adhesive bracket is 0.45
It has a width g of -0.55 mm and a depth h of 0.6-0.7 mm. The directional deviation of this kerf, i.e. the angle l shown in FIG. 4, can be up to 10", and the inclination angle of this kerf, i.e. the angle shown in FIG. 5, can be up to 25°. can.

Standardized base bodies can be created for different teeth depending on the actual shape.

By individually matching this standardized adhesive bracket made of glass-ceramic material to each case, it is possible to prepare each tooth using an orthodontic adhesive, such as polymethyl methacrylate, after pre-treatment of the enamel. By fixing the tooth to the tooth and fitting a highly elastic adjustment mounting frame into the tooth, any abnormality in the tooth attachment can be corrected.

6.7 and 8 show various shapes of adhesive replacement bone fragments made of glass-ceramic material, in which the upper part of the basal surface is T-shaped. Figure 8 shows one with a hook shape. The corners of this adhesive replacement bone fragment made of glass-ceramic material are likewise bent or rounded, and both sides m and n of the basal surface each have a length of 2.5-3 mm. , and the height 0 is at most 3 mn+. This adhesive bone replacement piece of mica-iolitic glass-ceramic material is fixed to the respective bone as described in the previous embodiment and is used, for example, to receive the rubber part.

The use of mica-iolitic glass-ceramic materials as head/neck surgical implants in accordance with the present invention will now be described in detail with reference to FIGS. 9 and 1O by means of two embodiments.

The sinus surgery implant shown in FIG. 9 consists of a bioactive peripheral zone p and a biocompatible core q of mica-iolite glass-ceramic material. The peripheral zone p and the core q are coated at their boundary r with colored oxides, such as FeO/Fe2O3, MnO2, (
:r20. , or by introducing NiO, etc.)
are visualized. The surface shape may be flat or curved depending on the respective anatomical conditions.

A strong bone union is ensured by the provision of the peripheral zone p made of highly bioactive glass ceramic material.

The core q has the effect of promoting the formation of outer skin cells due to the properties of the biocompatible cloud/iolite glass ceramic material used.

A second embodiment is shown in FIG. 10, in which one surface layer S is made of a highly bioactive glass-ceramic material and the other surface layer t is made of a biocompatible cloud 1. Made of iolite glass ceramic material. The two surface layers (S and t) are bonded to each other at their interface - in the manner described in the first embodiment above.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an example of an outer shell made of a glass-ceramic material according to the invention, and FIGS. 2 to 5 show various forms of adhesive brackets made of a glass-ceramic material according to the invention. FIGS. 6 to 8 show several JL body examples of adhesive substitute bone fragments made of glass ceramic material according to the present invention, and FIGS.
FIG. 0 is a cross-sectional view of 11 different examples of sinus surgery implants using glass-ceramic materials according to the present invention. a... Glass ceramic material layer b... Adhesive agent layer C... Synthetic resin layer d... Biting side edge e...
J, (base width f...base length g...kerf width h...kerf depth i...bracket height k...inclination angle l...direction deviation angle m, n... Basal side length 0... Adhesive alternative bone fragment height p... Highly bioactive ceramic material portion 9... Biocompatible ceramic material core r... Phase boundary S... Highly bioactive ceramic material layer t...biocompatible ceramic material layer Fl (3,1 FIG, 2 FIG, 4 FIG, 5 FIG, 6 n FIG, 7 RG, 8 FIG, 90 Inventor Frank Vogel Toitubu [F] 1 Inventor Werner Voge Germany Inse■
Inventor Michael Hopp Democratic Republic of Germany l800 Brandenburg H. Toss Stratsse 37 Democratic Republic of Germany 6900 Jena Democratic Republic of Schillerbach Strats 2337 Binz Erich
Aina Stratsse 16

Claims (17)

[Claims] (1) Fracture toughness is 2.0 MPa as K_I_C value
Up to m^1^/^2, hardness is HV_0_. _0_7 value is 300-1,000, compressive strength is 450N/mm
Up to ^2, linear thermal expansion coefficient is 75-125 x 10^-^7
(°K)^-^1, and has good chemical stability and high wear resistance, it has the following composition in weight percent: SiO_2 43- 50% Al_2O_3 26-30% MgO 11-15% R_2O 7-10.5% F^- 3.3-4.8% Cl^- 0.01-0.6% CaO 0.1-3% P_2O_5 0 .1-5% (with the exception that R_2O contains 3 to 5.5% by weight of Na_
2O and 4 to 6% by weight of K_2O)
, and contains mica in addition to 5-30% by volume of iolite as a crystal phase, and the structure is such that relatively large mica crystals with a size of 10-200 μm are embedded in the glass matrix phase. In addition, iolite crystals with a size of 0.5-5 μm are arranged in a distributed manner.
Glass-ceramic material as described above, characterized in that it has a structure in which platelet mica with a size of 5-5 μm may appear. (2) Glass-ceramic material according to claim 1, containing the components BaO, SrO and PbO, alone or as a mixture, in an amount of up to 8% by weight. (3) NiO, Cr_2O_3, MnO_2, FeO,
Glass-ceramic material according to claim 1 or 2, containing coloring components such as Fe_2O_3 and TiO_2, each alone or as a mixture, in an amount of up to 4% by weight. (4) It can be used for inlays, crowns, built-up structures, and bridges, especially for the lateral tooth area, and the external shape can be made from pure mica/iolite glass-ceramic materials according to the respective anatomical conditions. It can be molded separately or this mica-iolitic glass-ceramic material can be applied, e.g. by casting, onto a high-strength substrate, e.g. an Al_2O_3-based sintered ceramic material or metal, thereby forming this base. Glass-ceramic material according to any of claims 1 to 3 for use in various dental applications, which can be completely or partially encapsulated around the body. (5) Dental preparations, such as inlays, crowns, and bridges, made from pure mica-iolite glass-ceramic materials have a temperature of 80-120 x 10^-^7 (°K)^
Adjustable coefficient of linear thermal expansion in the range of -^1, bending strength at break higher than 80 MPa, compressive strength up to 450 N/mm^2, 300-800HV_0_. They have an adjustable hardness of _0_7 and a very good stability of class 1 or class 2 in chemical stability, such as hydrolysis resistance, and their dental moldings have a roughness with a depth of 0.15 μm. having surface roughness and radio-opacity, and being machineable at the same time, these parameters being adjusted to correspond to the properties of natural tooth enamel;
In the case of a bond consisting of a mica-iolite glass-ceramic material and a high-strength substrate such as metal or sintered corundum, the fracture strength is additionally 20%.
Glass-ceramic material according to any one of claims 1 to 3 for use in various dental applications, having an increased pressure of 0-400 MPa. (6) Claims 1 to 3 for use in various dental applications, which can be bonded to the hard material of the tooth by conventional fixing cements or by composite materials after silanization. A glass-ceramic material according to any of clause 5. (7) The vestibular side consists of a layer of mica-iolite glass-ceramic material, and the oral side consists of a layer of organic synthetic resin or a bonding material, in which case both layers are bonded by a layer of an adhesive agent. A glass-ceramic material according to any one of claims 1 to 3, which is used for an outer shell for covering a synthetic resin denture, a metal core, or a natural tooth. (8) The thickness of the glass ceramic material layer on the vestibular side is 0.5
mm or less, and is greater than 0.5 mm at the cut-off side edge, for use in an outer shell;
A glass-ceramic material according to any of claims 1 to 3 and 7. (9) A glass-ceramic material according to claim 7 or 8 for use in an exterior shell, in which the oral cavity side of the glass-ceramic material layer on the vestibular side has a surface area increasing structure. (10) Can be used for adhesive brackets and adhesive replacement bone fragments, in which case standardized moldings of these components have a wall thickness of at least 1 mm or more and a height of up to 3 mm;
Its basal surface may be curved or flat, with a roughness particularly greater than 5 μm in order to obtain a high adhesion force, and the width of its basal portion may be 2.5-6.0 mm, with both wings. the part has a straight or beveled edge, and the adhesive bracket has a kerf with a width of 0.45-0.55 mm and a depth of 0.63-0.71 mm; Due to the easy processability of the mica-iolitic glass-ceramic material, it can also be adapted to the mechanical requirements of the individual components, e.g. adhesive brackets, and the anatomical conditions of the respective tooth during clinical use. The individual shapeability is guaranteed, so that it is possible, for example, to form acute angles or to precisely match the base surface to its curvature, thereby making it possible to use, for example, orthodontic adhesives. In particular, when polymethyl methacrylate or various inorganic or organic bonding materials are applied, the high retention ability of the mica-iolite glass-ceramic material results in a high bonding strength of, for example, 18 MPa. Claims 1 to 3 for use in various applications in jaw orthopedics/orthodontics, where a favorable aesthetic effect is achieved based on the natural tooth-colored appearance of the mica-iolitic glass-ceramic material. Third
Glass-ceramic materials according to any of Clauses. (11) The kerf of the adhesive bracket has an inclined orientation with respect to the base surface, i.e., an angle of inclination of up to 25° and an angle of up to 10
The jaw shaping has a groove direction deviation angle of up to °, the kerf can be made of metal, and is preferably adhesively fitted into an adhesive bracket made of glass-ceramic material. Glass-ceramic material according to claim 10 for use in various applications in surgery/orthodontics. (12) The adhesive substitute bone fragment made of mica-iolite glass ceramic material has a basal surface with a side length of 2.5 to 3 mm, and the superstructure above the basal surface is T-shaped or hook-shaped. Glass-ceramic material according to claim 10 for use in various applications in jaw orthopedics/orthodontics, having the shape of . (13) When used as a graft for head/neck surgery, the graft is composed only of mica-iolite glass-ceramic material, or this biocompatible mica-iolite glass-ceramic material is combined with mechanical A glass-ceramic material according to any one of claims 1 to 3, which is made of a combination material with a highly bioactive glass-ceramic material that can be processed into. (14) When used as an implant for head/neck surgery, a combination material of the biocompatible mica/iolite glass ceramic material and the mechanically processable highly bioactive glass ceramic material is used. , glass-ceramic material according to claim 13, which can be produced in a softening phase on the basis of a correspondingly adjusted coefficient of linear thermal expansion. (15) When used as an implant for head/neck surgery, the phase interface between both glass-ceramic materials to be joined is coated with a small amount of a colored oxidizing agent prior to heat treatment of their respective starting materials. Glass-ceramic material according to claim 13 or 14, which is visible as a colored boundary layer by the introduction of the glass-ceramic material. (16) When used as an implant for head/neck surgery, it exhibits a high surface charge due to its special mica-iolite texture and its resulting residual glass phase. A glass-ceramic material according to any of clauses 1 to 3 and 13. (17) Claims 1 to 3 and 13 to 16, wherein when used as a graft for head/neck surgery, the implant can be processed using common surgical instruments during surgery. Glass-ceramic materials according to any of the following.