JPS6252142A - Colored calcium phosphate based glass - Google Patents

Abstract

PURPOSE:To obtain a calcium phosphate based glass, having a color similar to that of natural teeth and useful as artifical teeth, by adding a specific amount of one or more elements of Ru, Rh and Pd to a calcium phosphate based glass. CONSTITUTION:A calcium phosphate based glass is adjusted to a composition containing at least 70wt% calcium phosphate material at 0.1-0.7 atomic ratio of calcium to phosphorus. When the calcium phosphate based glass is used as artificial teeth, it is preferably crystallized. 0.001-1wt% at least one element of Ru, Rh and Pd is contained in the calcium phosphate based glass. A simple metal, oxide, hydroxide, halide, sulfide, etc., are added to a molten raw material for the glass to attain the aimed composition of the glass containing the element.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a colored calcium phosphate glass, particularly a calcium phosphate crystallized glass that has a color similar to that of natural teeth and is useful as an artificial tooth. .

(Conventional technology) Dental materials such as dentures, tooth roots, crowns, inlays, bridges, etc.
Various material compositions have been proposed as ceramic materials for living bodies such as artificial bones, and some are in practical use.

Among these materials, calcium phosphate glass has a composition similar to that of living tree bones, so it has fewer rejection reactions by living organisms.
It is attracting attention as a material for artificial teeth and bones. Furthermore, it is desired that such artificial materials, especially teeth, have a color and gloss similar to those of natural materials.

Examples of such glasses include Ca028-57 heavy glass,
A calcium phosphate-based crystallized glass with a composition of P2O572-43wt.11h, or a secondary crystallized glass with the addition of 10% by weight or less of Al2O3,51o2.8203k, or a yellow-brown calcium phosphate crystallized glass with the addition of Ni, Fθ, and Ceτ is proposed. has been done.

(Problem to be solved by the invention) However, although the former crystallized glass is white and translucent and has a gloss similar to that of natural teeth, the difference in color between it and natural teeth is noticeable, making it undesirable in terms of appearance. It has its drawbacks.

On the other hand, in the case of the latter type of glass, when the additive is N1, although it has the advantage of high coloring efficiency, it exhibits a dull yellow color, which is quite different from the color of natural teeth, and is l
(There is also concern that the elution of 1 may have an adverse effect on living organisms.

In addition, when the additive is Fe, the color development efficiency is low and it is necessary to add 0.5% by weight or more to effectively develop the color, and this not only impairs the translucency of the crystallized glass but also , the appearance becomes uneven and the color becomes grayish-brown and dark. Furthermore, when the additive is Ca, the coloring efficiency is low;
5% by weight or more of T- is required for effective color development, high strength,
Each of them has drawbacks, such as greatly impairing the inherent properties of calcium phosphate glass, such as easy moldability.

(Means for resolving the problem tM) Kinoe Akiban eliminates the drawbacks of these conventional methods and uses a phosphoric acid-based glass composition that has the same color and gloss as natural teeth and is unique to natural teeth. As a result of various research and studies with the aim of finding a solution, we have found that the above objective can be achieved by incorporating a specific amount of Ru or Rh%P (Li) into a calcium phosphate glass.

Thus, the present invention provides a colored calcium phosphate glass characterized by containing at least one element selected from Ru, Rh, and P(l) in an amount of 0.001 to 1% by weight.

In the present invention, it is necessary to employ 0.001 to 1 weight i% of one or more of Ru, Rh, and Pa contained as elements.

If the content is less than 0.001% by weight, the coloring efficiency will be low, resulting in unstable color development and uneven coloring.On the other hand, if the content exceeds 1% by weight, the color tone will be dark and the color tone will not match that of natural teeth. Since the difference between them is obvious, both are inappropriate insects. Among these content ranges, it is particularly preferable to use 0.01 to 0.1 wt % since it is possible to stably express the color and tone of natural teeth without any discoloration.

Contained Ru, Rh, P (L is any one or more of them as appropriate in the form of a simple metal, oxide, main oxide, -logenide, sulfide, nitrate, sulfate, organic acid salt, etc.) This is achieved by adding it to the glass fused image material.

Calcium diphosphate glass is calcium-based
As for glass, the atomic ratio of calcium to phosphorus is 0.
1 to 0.7, preferably 0.2 to 0.5t-70% by weight or more, preferably 85ti
It is desirable that the content is at least 100%. If the atomic ratio is less than 0.1, the resulting glass will have insufficient water resistance, and if it exceeds 0.7, vitrification may become uneven, so both are preferred. No ◎ Also, if the calcium phosphate content is less than 700% by weight, it is not preferable because the easy moldability and high strength of the glass may be impaired.

In addition, components other than calcium phosphate include Al2O3
, B2O3, Ga2O3, and rare earth elements are expected to improve the water resistance of the glass and have effects such as suppressing crystal growth.

Thus, it is desirable to crystallize such calcium phosphate glass when it is to be used as a biomaterial.

As the crystallization means, conventional means are usually employed.

As such a means, for example, a means such as keeping a calcium phosphate gas at 750° 0 for one hour can be adopted.

Further, it is appropriate to adopt a degree of crystallinity of about 30 to 98 degrees. If the degree of crystallinity was not within the above range t4, the improvement in toughness due to crystallization would be insufficient, resulting in a brittle crystallized glass, and conversely, if it exceeded the above range, cracks would easily form during crystallization. Neither is preferable since there is a risk that the strength of the crystallized glass will decrease.

(Example) Example work: CaCO3 powder equivalent to 25 weights as CaO, 1 weight s of Al2O3 powder and 0.08 as Ru
70 g of water was added to 100 g of mixed powder of RuO2 powder corresponding to ti%, and phosphoric acid containing H3P0j corresponding to 7 & 92% as P2O5 was added dropwise in a double bath, and the resulting reaction product was dried. , crushed to obtain powder.

This powder was heated at 400'O for 3 hours, then melted at 1250'O for 2 hours in a self-contained crucible, poured out onto a graphite plate, and slowly cooled. Thus, the atomic ratio of Ca7'P is 0.43.
．． A calcium phosphate colored glass containing 99% by weight of phosphorus and calcium was obtained.

After cutting the glass into a 1.5-inch thick, 5-inch square shape, 70 mm
Crystallization is performed by heat treatment at 0°0 for 2 hours.

The obtained crystallized glass had natural tooth-like luster, color and tone, and good translucency.

Example 2 CaCO3 powder corresponding to 24% by weight as CaO and A
Phosphoric acid containing H3PO4 corresponding to 73.98% by weight as p2O5 is dropped into a mixture of Al(OH)3 powder corresponding to 2% by weight as 12O3 and Rh g O3 powder corresponding to 1t% of Rho, 02i1t, The obtained reaction product was dried and then crushed.

After firing this powder at 400'O for 5 hours, it was placed in a platinum crucible.
The glass was melted at 250° for 2 hours, poured onto a graphite plate, and slowly cooled. Thus, a calcium phosphate-based colored glass with a Ca/P atomic ratio of 0.41 and a calcium phosphate substance of 98% was obtained.

After melting 2g of this glass at 1200°0 in a platinum crucible, we used the cost wax method to embed wax in the shape of the entire tooth crown, which was then incinerated and maintained at 500°0 in a phosphate-based investment material. Cast molding was performed using the centrifugal casting method. By holding the molded body together with the investment material at a temperature of 700° for 2 hours, it is crystallized to obtain a phosphocalcicum-based crystallized Gax stage complete dental crown. This has the luster, color, and tone of a natural tooth. It had good translucency.

Example 3 Ca (H2PO4) equivalent to 21 times 1* as CaO
2 powder and Al(O) equivalent to 4% by weight as Al2O3.
H) After mixing 3 powder and PdO powder equivalent to 0.04 weight ji as pa, further KP205 is 8.96
Next, add phosphoric acid containing H3PO4 corresponding to the amount of Ji.

The mixture was heat treated in a platinum crucible at 400°O for 4 hours, then melted at 1350°K for 1 hour, poured out onto an iron plate, and slowly cooled.

In this way, a calcium phosphate-based colored glass with a Ca/P atomic ratio of 0.36 and a calcium phosphate content of 96% by weight was obtained.

The glass was cast into the shape of a complete dental crown using the lost wax method in the same manner as in Example 2, and then crystallized to obtain a gold dental crown made of calcium phosphate crystallized glass.

This has the luster, color, and tone of natural teeth, and good translucency.90 Example 4 fcCaO1
2 weight, Al2O3 13% by weight, P2O574,93
After pulverizing a glass containing 87% by weight of calcium phosphate with a Ca/P atomic ratio of 0.21, flu
Ru(OH)3 powder corresponding to 0.05% by weight as L and PdCl3 powder of ozmit% as P(L) were mixed and melted again at 1350'0 for 30 minutes. The resulting glass was crushed to obtain an average particle size. A colored phosphoric acid A sium-based glass powder with a diameter of 5.2 μm was obtained.

After kneading 0.5 g of the glass powder with 3 mA of water to form a slurry, it was applied to the root of the crown of the colored calcium phosphate crystallized glass obtained in Example 2. Hold in oven at 120°○ for 10 minutes and dry at 700°0.
Hold the ratio for 5 minutes.

The obtained whole tooth crown has the same gloss, color, and tone as a natural tooth, and has a color distribution very similar to a natural tooth.

Example 5 Nine CaO15 were prepared in advance in the same manner as in Example 1.
% by weight, 36% by weight of Al2O, 578.93% by weight of P2O, a Ca/P atomic ratio of 0.24, and a glass containing 94% by weight of calcium phosphate.
．． RuO2 powder corresponding to 0.05% by weight, 0 as Rh,
Rh2o3 powder corresponding to 0.01% by weight, 0.01% by weight as pa.
135 again by mixing PdO powder corresponding to 0.01% by weight.
The glass obtained by melting at 0'O for 30 minutes was applied to a tooth crown made of calcium phosphate crystallized glass in the same manner as in Example 4, and heat-treated.

The whole coronum obtained had the same luster, color, and tone as natural teeth, and had a color distribution that closely resembled natural teeth.

Claims (1)

[Scope of Claims] 1. A colored calcium phosphate glass characterized by containing 0.001 to 1% by weight of at least one element selected from Ru, Rh, and Pd. 2. The calcium phosphate glass according to claim 1, wherein the calcium phosphate glass contains at least 70% by weight of calcium phosphate having an atomic ratio of calcium to phosphorus of 0.1 to 0.7. 3. The calcium phosphate glass according to claim (1) or (2), wherein the calcium phosphate glass is crystallized glass.