JPS5911845A - Production of implant material for artificial tooth and bone - 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 method for manufacturing an implant material for artificial teeth and artificial bones. More specifically, this article relates to a method for manufacturing an implant material for artificial teeth or bones made of hydroxyapatite that does not cause rejection, is easily assimilated, and has sufficient strength after being implanted in a living body. .

Hydroxyapatite exists as a main component of ceramics and bones in nature and in living organisms, and its chemical composition is expressed by the general formula % (however, it represents a two-digit coefficient of 7, and for hydroxyapatite in human bones it is 2K/). ).

We artificially create hydroxyapatite and implant it into living organisms.
Attempts to use it as a substitute for bones and teeth (d) have been carried out for a long time.Even if it is implanted in a living body, it does not cause rejection reaction L [1], but it There is a problem that it is weak compared to that, and its assimilation ability is not as good as T after being implanted in a living body.
The current situation is that it has not been put into practical use.

The object of the present invention is to provide water that does not cause a rejection reaction when implanted in a living body, is easily assimilated, and can exhibit sufficient strength in a cavity.
A method for producing an implant material for an artificial tooth or artificial bone made of acid apatite is proposed.

It is a problem that a hydroxyapatite molded product used as an implant material for an artificial tooth or an artificial bone I11 is assimilated into the living body after being implanted in the living body. To achieve this, it is not necessarily necessary that the material be dense and have high strength, but it must have the following properties.

1) It is necessary to have physical properties that approximate the hardness and strength of the bones and teeth to be replaced. If it is too hard or strong, it will put an excessive burden on the natural teeth and bones of the living body that connect or bite with it, while if it is too soft or weak, it will be of no use.

5゛′) It shouldn't be too crowded.

5) The Oa/P ratio in hydroxyapatite must be controlled and maintained so that it can be easily assimilated into living tissues.

As shown in the above general formula, the chemical composition of hydroxyapatite has a group of crystal phases whose crystal structures are very similar but whose chemical groups I& are different. That is, 2 shown in the formula
If 114 is different, the chemical properties will change.

Therefore, in order to facilitate assimilation into living tissues, it is necessary to accurately control the atomic ratio of phosphorus to calcium to a ratio that corresponds to bones or teeth in living bodies.

Conventional apatite molded products have a chemical composition.

That is, apatite powder having a composition of Ca1o(PO2)6(OH)2 is synthesized, and the particle size is adjusted by crushing or pre-calcining, and after molding this into a green compact,
It was manufactured by pressureless sintering or hot pressing at 7300°C.

According to this method, the chemical composition is constant and also.

Since it is simply molded and fired, it has the disadvantage of meeting the three requirements mentioned above as an implant material for artificial teeth or artificial bones, especially that it is difficult to assimilate into living tissue.

The present inventors solved the conventional drawbacks and
As a result of research, we have made it possible to change the molar ratio of calcium to phosphate groups in hydroxyapatite within a certain range,
When hydroxyapatite powder having a certain amount of water (f1) is sealed in a sealed tube and fired under pressure under conditions of 1), needle-shaped apatinide powder is formed. '4 It is possible to obtain a sintered body with a structure in which crystals are intertwined.The porosity of the sintered body is unprecedented.

It has been found that the molar ratio of calcium to phosphate radicals can be arbitrarily controlled by the composition of the composition sealed in the sealed tube and the processing conditions. The present invention was completed based on this research fact.

The gist of the present invention is that the molar ratio of calcium to phosphate radicals is 9 to /θ to 6, and the water content is 0.7 to 0.0 at 7000°C. A method for manufacturing an implant material for an artificial tooth or bone.

A sintered body having an entangled structure a of apatite needle crystals obtained by the method of the present invention is! It is obtained by impregnating it with a constant amount of water for 1 hour, sealing it, and firing it under pressure.

A sintered body with such a structure has both the porosity and strength required as an implant material, and has excellent effects in that it is easily assimilated into living tissue, and the molar ratio of lucium to phosphate radicals is high. The ratio needs to be in the range of wo to z to /θ to ot. This is an artificial tooth.

This is because it is within the composition range of artificial bones.

In order to obtain an apatite sintered body in which only hydroxyapatite crystal phases with an Oa/P molar ratio close to 9/O are entangled, the firing temperature is 300°C or lower and the pressure is 1000%.
It is sufficient to hold it under the above conditions for 3 hours or more, preferably for 70 hours or more.

To obtain 1000 Ky/cm2 below soo℃
It is sufficient to maintain the temperature for more than 1 hour, preferably for 3 hours.

In order to obtain the same sintered body with the Oa/P molar ratio /θ/B, the Oa, /P molar ratio 9/B, q, s/l is required.
It can be obtained by firing without any upper limit wetting IW limit.

Add water to the apatite powder.

It is necessary to contain 1% of Kokichi. This water separation has the effect of creating pores in the resulting sintered body. When heating and sintering in a sealed tube, water is uniformly dispersed inside the sealed tube by pressure and heat from outside the sealed tube, and the sintering process occurs. It promotes the formation of acicular apatite microcrystals and generates pores.

Water content is 0. / *If the amount is less than %, the microstructure of the sintered body obtained will be an aggregate of columnar crystals, which is undesirable.
When the amount of tr, o H is exceeded, the porosity is 307! vol1
%, which lowers the strength of the sintered body, so it is preferable. .

7□%! l□0. . □A+1 fitIvol% and above, and 3v%, the porosity is equal to 1vol%. This porosity is greatly influenced by the moisture content, but is also influenced by the firing temperature, pressure, firing time, and temperature increase program. The porosity decreases as the pressure increases, the firing time increases, and the temperature decreases. It is also possible to adjust the temperature by a temperature raising program such as holding at a low humidity to achieve a low porosity and then curing at a high temperature to measure grain growth.

The raw material hydroxyapatite powder is suitable as it is, or aluminum is suitable at low temperatures. Preferably, the material has black plasticity and gas impermeability. However, it is not limited to those other than the above.

The processing conditions in the method of the present invention require that s, ooo to 3θ and 2/cIn2) pressure be 1.2oo to 10oo°C.

The pressure is necessary to reduce the porosity of the resulting sintered body to a desired value, and the higher the pressure, the shorter the time required to reach the desired porosity. That pressure is 3θ
If the porosity is lower than Ky/cm2, the porosity will be around 3θVOI% and the strength of the sintered body will be low, which is undesirable; Made by S! This is not desirable because it causes problems in terms of sex. Favorable L < Hso.

~, 2000 K97 cm2.

The higher the firing degree, the faster the densification and crystal growth. Therefore, the processing time is shortened (4
However, if the temperature exceeds 1000 DEG C., the fine needle-shaped crystals', intertwined structure will be lost and the individual crystals will become thick and short, so the temperature must be 100 DEG C. or less. On the other hand, when the firing temperature is low, the growth rate of the crystals constituting the sintered body is low, and a long time is required to generate the intertwined structure of needle-like crystals.

It requires 70 hours at 300°C, and it requires a much longer time at a temperature lower than 200°C, so it cannot be cut into 4 pieces.

゛=屓1CHO↑＠ IIJJ (D li H”'C11
C->t"411" [bl, n17t ・It is generated from four notes, and the voids that occur between needle-shaped crystals are voids. The diameter of the pores is several times the diameter of the sword-shaped crystal within one block.
l-, isu, - Almost uniformly dispersed in the sintered body. Since the sintered body has such a structure, when it is inserted into each living body, the raw silk will flow from the empty Fl of the sintered body to fφ person 1. It has a 4″1 character that is easy to assimilate.

In addition, the sintered body can be formed into the shape of a d-bone by either sintering the E material powder after plasticizing it or by containing moisture in the hydroxyapatite powder that encapsulates the sintered body in that shape. By adjusting the water content, it is possible to obtain appropriate pores in the sintered body, and it is also possible to obtain a sintered body having a structure in which nail-like crystals are entangled, which could not be obtained by conventional methods. Still, Oa /
By adjusting the ratio of P, a sintered body with a composition suitable for the purpose of use can be obtained, and by adjusting the firing conditions, appropriate crystal and pore sizes can be obtained. An implant material for artificial bone can provide excellent effects and effects.

Example 18 Using GaHP04・, 2H20 as a starting material, hydroxyl abatai) (Oa, H(PO4)60H・+3 H2O)
and mix slaked lime with it to make the Ga/P molar ratio 1.
A composition adjusted to 0/t was prepared. This composition was sealed in a metal sealed tube, and the sealed tube was heated at sso℃, /4100K.
9/cm2 for 3 hours. The porosity of the obtained fired body is: inlet/outer []4・volume of pores, /7 VOI
%, volume of pores that do not have 1 in and out [1] 0. ．． 2jv
o1%, average particle diameter 0.7 μm.

A fired body was obtained that had a structure in which needle-like crystals with a length of 7 to 2 μm were intertwined.

Example 2 0a9.48 (HFO2) 0.52 (po4)
Hydroxyapatite powder having a composition of 5.48 (OH) L48' nH2O was reduced in moisture content, dried to a concentration of 5%, sealed in a metal sealed tube, and heated to 3SO°C, /OooKy/ It was held for an hour in cm2. It was something worth getting. The Oa/P of the sintered body was yz/y at night, and no phase other than hydroxyapatite was detected.

Patent applicant Director of the Institute for Inorganic Materials, Science and Technology Agency 1°1 Ma Procedures Amendment 1, Description of the case 1982 Patent Application No. 122292 2, Name of the invention Method for manufacturing implant materials for artificial teeth or artificial bones 3. Relationship with the case of the person making the amendment Patent applicant 5. The number of inventions that will be increased by the amendment None 6. The scope of the patent specification of the specification subject to the amendment and the detailed description of the invention should be closed from 3,000 to 3,000. Under a pressure of 30 Ky/cm2, 2
1. A method for producing an implant material for an artificial tooth or artificial bone, which comprises firing at a temperature of 00 to 1000°C. ” (2) On page 5, line ~ /θ line “The gist of the present invention is...
... hydroxyapatite powder" should be corrected as follows.

``The gist of the present invention is to add water to raw material powder or hydroxyapatite powder having a composition equivalent to hydroxyapatite with a molar ratio of calcium to phosphate radicals of ?6 to /θ to 2, and add moisture to 0./~g, o weight%. (3) Page B/line ``The hydroxyapatite powder is'' is corrected to ``The raw material powder having a composition equivalent to hydroxyapatite is''.

(4) Insert the following sentence between line j and line 4 on page 6.

“The raw material powder with a composition equivalent to hydroxyl abamate used in the method of the present invention is tricalcium phosphate, tricalcium phosphate,
Calcium hydrogen phosphate, hydroxyl, ) 1 -4 batite dicalcium phosphates alone or mixed with each other, if necessary by adding calcium hydroxide, the ratio of calcium to phosphate radicals is 9 vs. Otsu~/θ
If the composition is mixed so that it is maintained within the range of
After treatment, a sintered hydroxyapatite body is obtained. ” (5) Change “Hydroxyapatite” in two lines from the bottom of page A to
O4・, 2H20=-...made" is corrected as follows.

"0aHP04・, 2H20 as a starting material, Oa,
Hydroxyapatite with a composition of H(PO,), OH・3.3H20 is made, and slaked lime is mixed with this to make a composition in which the molar ratio of 7a/P is adjusted to 10/O, and this is used as a ring material. It was made into a powder.'' (8) No. 1/g, ? line, insert the following sentence after ``obtained.''

"No phase other than the hydroxyapatite phase was detected." (9) - Correct "hydroxyapatite powder" to "hydroxyapatite crystal powder" in line 6 of page 1.

JP”859-11845(5)

Claims (1)

[Claims] Calcilla (hydroxyapatite powder with a molar ratio of M to phosphate groups of 9 to 6 to θ to O and a water content of 0./ to R and O by weight %) is sealed in a sealed tube. 5,000~3
A method for producing an implant material for an artificial tooth or bone, which comprises firing at 200 to 1000°C under a pressure of 0 kg/cm2.