JPS5950046A - High foul resistance mica composition for dental goods, dental treatment or like - 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 The present invention relates to a novel material for use in dental supplies, dental treatments, etc., and more particularly to a novel mica yarn dental composition with excellent resistance to contamination during use.

The main purpose of dentistry is to replace or correct damaged or deformed teeth by fabricating and installing dental structures. Commonly used such dental structures include dental appliances such as tooth bases, bridges, orthodontic brackets, accessories for such dental appliances, prosthetic appliances such as inlays, onlays, partial dentures or These include complete dentures, crowns or caps.

These dental structures are inert in the mouth, can resist masticatory forces, can provide a desired anatomical shape, and have an aesthetic appearance similar to that of natural teeth. However, there are few materials that simultaneously satisfy all of these requirements.

Currently, dental structures that can accommodate several people are generally made of alloys, porcelain,
Made of amalgam, acrylic polymer, or a combination thereof.

Alloys and amalgams are undesirable when aesthetics are particularly important because they differ significantly in appearance from normal teeth. Porcelain clay and acrylic polymers are often weak and cannot withstand chewing.

There are composite structures, for example, those in which the lower structure is made of metal and the upper structure is made of porcelain clay to improve the appearance, but such composite structures require advanced technology and,
The bulk density is often too high. Conventional dental structures thus represent a reasonable compromise between various requirements.

As a recent promising research in the field of dental treatment, the use of mica-based glass-ceramics to fabricate dental structures has been proposed by CoHo Pameijer et al.
cal Properties of a Ca5tab
le Ceramic Dental Restora
tiveMaterial ) J AAD 几 Abs
tract 827, J.

Dent, Res, 59 (March 1980 issue)
, p. 474. Glass-ceramics can be made by heating glass in-situ (in 5ite) by suitable heat treatment.
) is a semi-crystalline material obtained by controlled crystallization and was first disclosed in US Pat. No. 2,920,971. Since glass-ceramics are primarily composed of crystals (more than 50 volume fractions are crystals, often more than 90 volume fractions are crystals), they have a higher concentration of the above-mentioned main constituents than the starting glass or precursor glass from which they are made. It exhibits properties very similar to those of the glass phase.

Thus, the properties of glass-ceramics can vary widely depending on the particular crystalline phase present therein.

Among the more recently developed glass-ceramic materials are mica-containing glass-ceramics first disclosed by US Pat. No. 3,689,293. Mica-containing ceramics are
It has relatively special properties that make it particularly desirable for making dental instruments and structures. That is, the ceramic is not brittle and can withstand point impacts without propagating fracture. Thus, mica-based glass-ceramic bodies can be pushed through point hardness tests that would destroy conventional porcelain clays.

The reason for this behavior is that the mica crystal, which is the main component, can flow plastically to some extent by sliding along the base surface or the arm opening surface for 5 m.

The glass ceramic of US Pat. No. 3,689,293 is described as a machinable glass ceramic because it can be cut and shaped using conventional metal processing equipment and processing methods. The crystalline phase that is the main component of the ceramic is 7A/olophrogobite (fluor
rphlogopite) solid solution (e.g., fluorophlogopite [KMg3AlSiaOtoF2]
3BSi3010F2] crystal). Although these materials have excellent machinability, C,Ho
Pameijer et al. in the above-mentioned paper suggest that tetraspherized mica glass ceramics should be used to obtain dental reinforcements. This kind of glass ceramic is
As described in U.S. Pat. No. 3,732.087,
The crystalline phase, which is the main component, is tetraspherical fluoromica (
tetrasilicicfluormica) (
For example, it is characterized by containing KMg2.5si40toF2). Further description of the use of these materials for dentistry can be found in the already published European patent application EP 22,655.

Tetraspherized fluoromica glass-ceramics differ from glass-ceramics containing fluorophrogobite and boron fluorophrogobite in that both M13 and B+3 are removed from the crystal structure due to the added silicon (S14+) component. . With such substitution, the tetraspherized glass-ceramic material exhibits better chemical durability and mechanical strength. The above-mentioned US Pat. No. 3,689,293 and US Pat. No. 3,732,087 are cited herein for reference in the description of the known mica-based glass-ceramic materials mentioned above.

The present invention now relates to improvements in tetraspherized mica glass ceramics for use in the production of dental structures and other applications; the ceramics according to the invention have significantly improved resistance to contamination. Contamination resistance is most important in applications such as dental prosthetics, but is also desirable in other applications where frequent contact with contaminating media is expected (eg, tableware).

According to the invention, small amounts of M2O3 and/or Z
By controlling the addition of rO2 to a specific tetra-fluoromica composition, a thermocrystalline glass for tetra-fluoromica glass-ceramics with significantly improved contamination resistance can be obtained. More specifically, the present invention relates to thermocrystallizable glasses and stain-resistant tetra-spheroidal fluoromica products (eg, dental structures) made by in 5ite crystallization of the glasses. Preferred compositions of the glasses and glass-ceramic products of the invention are, by weight, approximately 45 to
70% Sioz, 8-20% MgO, 8-15'
% MgF 2.5-35 cm, where R20 is in the range of 5-25 cm, and O-
RbzO of 20.0-23 inches and O-25 of 20 inches
RO is in the range of 0 to 20 oxides, and RO is comprised of an oxide selected from the group consisting of 8rO, BaO and CdO. , furthermore, 0 to 7 zrO2
, containing 0-2% A7203, Zr0z+AJ203
The total amount of is 1 to 9%. Additionally, optional components that are advantageous when used in dental applications include 0 to 7% TiO2 and 0
~10 conventional glass colorants are included. Of course,
In addition to the above components, other components known to be compatible with tetraspherized fluoromica compositions may also be added, such as oxidation of metals from group I of the periodic table. These include, but are not limited to, oxides of metals and transition metals.

Glasses in the above composition range can be prepared in 5ite by nucleation and crystallization heat treatments as conventionally used to produce glass-ceramics.
) can be crystallized into glass-ceramic products.

A preferred heat treatment involves heating the glass to a nucleation temperature of about 650-850°C for a time ranging from about 0.25 to 10 hours, and subjecting the glass to a nucleation temperature of about 650-850°C for a time ranging from about 1-100 hours.
1200°C.

The invention will be explained in more detail below with reference to the accompanying drawings. This figure shows the high stain resistance of the glass-ceramic material obtained according to the invention.

A method for objectively evaluating the color of candidate materials that can be used as teeth and dental structures has recently been developed by G.

“Evaluation of the color of cast ceramic reinforcements” by Qrossman et al.
1or ofa Ca5t Ceramic Re5t
orative Material) JAAI)R
Abstract 1094. J.Dent, 1
(Ies,.

59 (March 1980 issue), page 542. This method uses a Chromascan shade scanner (5ter, Sta., Connecticut, USA).
It consists of analyzing the light reflected by a sample of the material to be evaluated using a photometer, such as a photometer (available from Ndent, Inc.). By operating this scanner, the intensity in the red, green and blue spectral regions of the light reflected by the material to be evaluated is measured, and the obtained values are used to determine the hue (proportion of the three primary colors) of the reflected light. , calculate saturation (color saturation) and lightness (overall brightness on the white-black scale). The stain resistance of a certain candidate material can be determined objectively by performing the above color evaluation before and after subjecting the material to a stain treatment.

Using the method described in the above-mentioned paper by Grosman et al., the hue is approximately 0.2 to 0.8 and the saturation is approximately 20 to 18, within the coloration range that normally occurs in human teeth.
0, and the brightness was found to be in the range of about 350-800. When developing prosthetic materials, it is desirable that the characteristics of the reflected light be within this range.
This is usually achieved by adding colorants to the material. What is important is that the material does not show significant changes in color during use, so that the development of the basic material for manufacturing the structures is directed towards obtaining good stain resistance.

Coffee is a contaminating medium that has received particular attention when developing dental prosthetic materials. As far as the field of dental applications and/or cooking is concerned, coffee belongs to one of the most severe polluting media. One of the currently trusted contamination tests to evaluate and compare the contamination resistance of candidate materials is to subject samples of a particular material to 80°C with exposure intervals of every 7 days.
The coffee contamination test consists of exposure to coffee. This test produces measurable changes in hue, brightness, and saturation in many ceramic materials.

The best contamination resistance according to the invention is A720+ and Zr
obtained by a composition containing both O2. To demonstrate the effect of the addition of small amounts of alumina and zirconia on the stain resistance of glass-ceramic prosthetic materials, the behavior of six glass-ceramic materials in the coffee stain test described above was compared. The compositions of these materials are listed in 1ff below and are based on the batch composition on a weight basis. Basic ingredients 5i
(The total amount of h, K2O, MgO and MgFz is 100
parts, and therefore the values of those components given in the table correspond to the weight percentages of the underlying glass.

The remaining components can be considered as additive components added in excess of 100 parts when the base glass composition is 100 parts. As can be seen from the table, Examples 4-6 correspond to Examples 1-3, respectively, except that the former contains a small amount of AJlzO3.

Chapter ■ Table 5i0260.564.061.160.564.06
1. lK2O15,514,415,715,514,
415,7MgFz 10.59.710.410.5
9.710.4Mg013.511.912.813.
511.912.8ZrO22,02,01,02,0
2,01,0TiO2--3,0-3,0 A1203--0.50.50.5 Colorant--0,65--0,65 All of the materials shown in Table Mica glass-ceramic compositions containing Sioz, K2O, MgFz and MgO as the basic crystal-forming components, and in some cases 'rio2 and a colorant (to adjust the color of the reflected light). Contains. Form glass batches from molten glass of each composition,
Glass ceramics were then produced from each composition by converting the glass batches into glass ceramics with high crystallinity through heat treatment. The maximum crystallization temperature was in the range of 1075-1090°C and the crystallization time was 6 hours. Glass-ceramic patches were cut into plates approximately 0.25 inches thick and polished prior to testing.

In the contamination test, we first check the color of each sample,
The sample was then immersed in coffee for 7 days at 80°C, after which the sample was removed, rinsed with deionized water and checked for color again, and finally a third color test after 1 minute layering with commercial toothpaste. I did this. The data obtained from these tests are shown in the following table. In this table, 6
For each type of sample, the color before staining (initial color), the color after staining and washing (color after staining/washing), and the color after staining and brushing (color after staining/polishing). The hue (i(), brightness (V), and chroma (C)) of .

17- Examining the data shown in Table 1 and similar data obtained for glass-ceramic products having the composition shown in Table 1 but with a different heat treatment and/or a different surface finish, it is found that they contain only ZrO2 Although the contamination resistance of those having compositions 1 to 3 is tolerable to some extent,
It is recognized that the products to which alumina is added as shown in compositions 4 to 6 have further improved stain resistance, regardless of the thermal history of the glass ceramic or its surface finish. As the data in Table ■ show, such additions are most effective at reducing changes in brightness and/or saturation, but in addition, they often also stabilize color. Is recognized.

The color stabilizing effect of the addition of alumina is shown in the accompanying drawings. This figure shows the data for samples 1 and 4 in Table 1, as well as the data for samples of the same composition as those samples at the maximum temperature for 12 hours instead of 6 hours.
Figure 3 shows the color data from the coffee stain test for time crystallized samples. In the graph of the same figure, the horizontal axis represents the stage at which the contamination test was conducted, and the hue, brightness, and saturation are plotted on the vertical axis. The stages tested were before contamination (I), after contamination and cleaning (S/
) L) and after staining and polishing (S/B). The data shown shows that the compositions of Examples 1 and 4 of Table 1 were tested for 6 hours (denoted as 6-I]几H'r) and 12 hours (
12-H⇠f (denoted as 'I') in situ
5ite) This is the value for the crystallized product.

According to the invention, the best fouling resistance is obtained for compositions containing both M2O3 and ZrO2, while Zr
Using O2 alone also significantly improves contamination resistance. For example, in terms of weight, 5i02 is approximately 60.5 inches, ■2 is 3.5 inches.
0.14.591+ MgO and 11.5% MgF
2 as a first composition, a composition containing these components in the same ratio and further comprising 2.5 weight percent ZrO2 as a second composition, and these compositions were subjected to the same heat treatment. After application, when subjected to a coffee stain test, the first composition showed light staining, while the second composition did not show any staining. This fact indicates that the resistance to acid of the second composition (measured by the weight loss of the sample after 24 h at 95°C in J solution) is greater than that of the first composition. It was recognized despite being slightly lower.

Based on the above data and others, preferred composition ranges for a thermocrystalline glass and a four-balled mica glass-ceramic product with stain resistance have been established. They are particularly suitable for obtaining dental structures and are based on mica-based compositions containing ZrO2 and preferably #zO3 to increase the stain resistance. That is, the composition of the glass and the product is approximately 45-70% SiO2, ~20% MgO2, calculated as batch components, in weight percent
0chi, MgF28~15chi, K2O5~20%, Al1
2030~2chi preferably 0.05~2%, Zr0z
0.5-7%, total amount of Zr0z + AlzOa 1-9
q6, T1020-71%, and a total amount of conventionally used glass colorants from 0 to 10%. Colorants include manganese oxide, iron oxide, nickel oxide, or any other compound or element conventionally known for use in glass layer colors. The presence of zirconia in these compositions not only increases resistance to acids, but also controls the translucency of the glass-ceramic product and prevents recrystallization of the glass-ceramic at crystallization temperatures. This is particularly important to ensure that

The mechanism by which coffee and other contaminating media permanently stain tetraspherized mica glass-ceramics is not fully understood, but factors other than composition, such as the thermal history of the glass-ceramic and the nature and degree of crystallization of the glass-ceramic, may also be involved. It is also believed to have some influence on the final contamination resistance of the material. However, holding such other factors constant, the addition of small amounts of zirconia and alumina to a given composition to increase its durability has made it possible to improve the durability of tetraspherized fluoromica for use in dental structures and other applications. The composition can be significantly improved.

[Brief explanation of the drawing]

The figure is a graph showing the contamination resistance of a glass-ceramic material according to the invention. Oral engraving (no change in content) 11111 Shiki Akira〆〆(02 □輔葭-2cco” 1111---------------------% Sakame 1 Procedural amendment (method) % Formula % 1 Indication of the case Patent No. 159417 of 1982 2 Title of the invention Mica composition with excellent contamination resistance used for dental supplies, dental treatment, etc. 3 Relationship with the amended party case Patent applicant 4 agent January 5, 1980 (Shipping date: January 25, 1988) 6 Number of inventions increased by amendment None 7
, Target of correction Drawing 8 Contents of correction
Correct the drawing into an inked drawing. 243

Claims (3)

[Claims] (1) Calculated as a batch, in weight percent,
5iOz 45-70%, MgO8-20%, MgF
28-15%, R, 20+ RO5-35%, A72o
30~2%, Zr020~7%, A120a + Zr
021-9%, T1020-7%, and a total amount of glass colorant 0-10%, provided that R20 is in the range of 5-25 inches and 200-20%, Rb200-23
selected from the group consisting of C520o and C520o to 25chi, and has an RO in the range of 0 to 20% and contains 8rO, BaO
and CdO, the thermocrystalline glass being capable of being thermally crystallized into a four-balled fluoromica glass-ceramic material having excellent contamination resistance. 1- (2) Weight percentage when calculated as a batch;
5iO245~70chi, Mg08~20%, MgF28
~15chi, R20+RO5~35chi, Al2030~2
q6, Zr020-7%, total amount of Al2O3 + Zr0z 1-9t, TiO20-7t, glass colorant 0
~10%, provided that RzO is in the range of 5 to 25 and selected from the group consisting of 200 to 20, B200 to 23%, and C8200 to 25, and 11
, 0 is in the range of 0 to 20 inches and has a composition selected from the group consisting of SrO, BaO and CdO, and has excellent contamination resistance. (3) The glass-ceramic product according to claim 2, which forms a dental structure. 2-