JPH01139516A - One paste-type restorative material - Google Patents

Abstract

PURPOSE:To obtain the title restorative material resistant to hardening during storage, having easy handleability such as dispensable even at a small amount and useful for dental and orthopedic use, etc., by mixing tricalcium alpha-phosphate powder, etc., with a specific kneading liquid and filling the obtained one-paste composition in a syringe. CONSTITUTION:Tricalcium alpha-phosphate powder, tetracalcium phosphate powder or a mixture of tetracalcium phosphate powder and other calcium phosphate powder is mixed with at least one kind of a kneading liquid selected from vegetable oil, polyhydric alcohol, polyalkylene glycol, silicone oil and liquid paraffin and the mixture is filled in a syringe. The ratio of the powder to the liquid is adjusted to get a paste having a viscosity of 1-1,000 poise. The above restorative material forms as excellent hardened hydroxyapatite in contact with water and the workability in operation can be improved. It can be used in dental field such as a root canal restoration intermediate material and pulp capping or in orthopedic field such as a bone cement and bone filler.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel one-paste type restorative material. Specifically, it is a one-paste type restorative material filled in a syringe, which is extremely easy to store and handle, and which produces a good hardened hydroxyapatite body upon contact with water.

[Conventional technology]

In general, dental restorative materials such as root canal filling materials, backing materials, and covering materials are required to be hardenable materials that have good affinity with teeth and have little harmful effect on living organisms.

Conventionally, compositions that produce hydroxyapatite (HAP), which is the main component of bones and teeth after hardening, have been proposed as such hardenable materials.For example, tetracalcium phosphate and/or α-tricalcium phosphate have been proposed. A composition comprising a kneading solution of water or an aqueous organic acid solution is known.

[Problem that the invention seeks to solve]

However, in order to avoid hardening during storage, the above composition is handled in two parts: a powder of tetracalcium phosphate and/or α-tricalcium phosphate and a kneading liquid, and these are mixed immediately before use. It was mixed and used on a tray. Therefore, in addition to operational problems such as the need for skill to prepare a paste with a suitable viscosity for treatment, a separate device was required to fill the treatment area. Also,
Even when only a very small amount is required, such as in the case of root canal filling material, a large amount of material must be kneaded, which poses an economical problem.

[Means for solving problems]

The present inventors have conducted extensive research in order to solve the problems of the above-mentioned compositions using tetracalcium phosphate or α-tricalcium phosphate. As a result, by mixing the above-mentioned calcium phosphate powder and a specific organic compound that can replace water to form a one-paste paste and filling it into a syringe, we were able to: ■ prevent it from hardening during storage, and ■ prevent narrow spaces such as root canals. It can be directly filled into the root canal, and has excellent handling properties such as being able to take out the required amount at will, even if it is only a small amount.Furthermore, when filled into a root canal, etc., it reacts with moisture in the body and produces hardened hydroxyapatite. They have discovered that it is possible to do so, and have completed the present invention.

The present invention provides α-tricalcium phosphate powder, tetracalcium phosphate powder, or mixtures of tetracalcium phosphate powder and other calcium phosphate powders (hereinafter collectively referred to as C
A one-paste type restorative material made by filling a syringe with a paste consisting of P powder) and at least one kind of kneading liquid selected from the group consisting of vegetable oil, polyhydric alcohol, polyalkylene glycol, silicone oil, and liquid paraffin. It is.

In the present invention, PC powder, which is one component of the paste, is
α-tricalcium phosphate powder, tetracalcium phosphate, or a mixture of tetracalcium phosphate powder and other calcium phosphate powders. The above tetracalcium phosphate may be produced by any method. For example, the raw material is C
CaC01+Cab, Ca(011)z, as a source
PzOs, l13PO4, N11411z as P source
POt.

(NII4) tHPOa+ CaHPO4.211zO containing both Ca and P.

Ca1lPOt+ Ca(HzPO*)z, CazP
zOt etc. can be used. In addition, there are various manufacturing methods depending on the raw material, and it may be appropriate to adopt them depending on the raw material. Among them, 7 obtained by calcining CaHPO44HtO
A dry manufacturing method in which Ca2PzOt is mixed and fired with CaC0z is excellent and preferred.

This reaction is 2CallPO4-211,0-r-CazPzO,
+ 5H,0CazPzOt + 2CaCO3
The reaction formula is -1 → CazPzOq + 2COz, and if it is fired at 1200℃ or higher and then rapidly cooled outside the furnace, or if it is fired at 1200℃ or higher in a nitrogen atmosphere, pure tetraphosphoric acid will be produced without transitioning to hydroxyapatite. Calcium is obtained.

Further, for the production of α-tricalcium phosphate, any known method using the above-mentioned raw materials can be employed without particular limitation.

Further, other calcium phosphate to be mixed with the above-mentioned tetracalcium phosphate has a Ca/P molar ratio of less than 1.67 in order to efficiently generate hydroxyapatite. For example, CaHPO4, Ca)IPO
4・211□o, Cam1lz (PO4) b ・
511Zo, Cas (PO4) z +CazPz
Among these, Ca11PO< and Ca11PO4.znzo are particularly suitable for improving the mechanical properties of the resulting cured product.

In the above mixture of calcium phosphate powder and tetracalcium phosphate, the mixing ratio is Ca/P molar ratio of 1.3.
It is preferable to adjust the ratio to 1.9 in order to efficiently generate hydroxyapatite.

In the present invention, the particle size of the PC powder is not particularly limited, but considering the kneadability with the kneading liquid, the production rate of hydroxyapatite, the surface condition of the resulting cured product, etc., the particle size is 0.01.
Those having an average particle diameter of ~500 μm, preferably 0.1-100 μm are suitable.

In the present invention, the kneading liquid includes olive oil, peanut oil,
Vegetable oils such as rose oil, castor oil, almond oil, polyhydric alcohols such as glycerin, ethylene glycol, propylene glycol, polyethylene glycol (PEG)
, polyalkylene glycol such as polypropylene glycol (PPG), silicone oil, and liquid paraffin.

Among these, polyhydric alcohols and polyalkylene glycols, which have a particularly high affinity for water, can be easily replaced with water and can yield a paste that exhibits good hardening properties upon contact with water. In addition, it is preferable because it is less harmful to living organisms.

In the present invention, the powder/liquid ratio of the PC, H powder and the kneading liquid may be determined as appropriate to obtain a suitable viscosity depending on the application. Generally, the powder/liquid ratio may be adjusted so that the viscosity of the resulting paste is within the range of 1 to 1000 poise, preferably 10 to 500 poise.

For example, when used for root canal filling, the viscosity of the paste is 2.
It is preferable to adjust the powder/liquid ratio to 0 to 200 poise.

Further, the method of mixing the PC powder and the kneading liquid is not particularly limited, and any mixing method using a known mixing material may be employed without any restriction. For example, a method using a mixing material such as a crusher, ball mill, Nigu, mixer, etc. is common.

Further, other components may be added to the paste of the present invention, if necessary, within a range that does not significantly adversely affect the curability. For example, in order to provide X-ray contrast properties, barium sulfate, barium glass, strontium glass, zirconia, iodoform, etc. are added to 100 parts by weight of the paste.
It is preferable to add up to 50 parts by weight. In addition, in order to adjust the curing time and paste viscosity, hydroxyapatite, silica, CaPz + TtOz + calcium hydroxide,
Alumina, sodium phosphate, ammonium phosphate, etc. can be added.

Further, the syringe used in the present invention is not particularly limited, and any known syringe can be used without restriction. Typical examples include the syringe type shown in FIG. 1, and the disposable tip type used for filling dental composite resin syringes as shown in FIG.

In either case, the shape of the tip can be made thicker or thinner depending on the purpose of use, and it can also be bent to make it easier to manipulate. Further, it is desirable to cover the tip with a cap 4 to prevent it from reacting with moisture in the air during storage. Typical examples of the above-mentioned syringe type extrusion structure for extruding the paste 3 include a structure in which the piston part 1 is pushed linearly, and a structure in which the paste 3 is extruded while rotating using a screw type. In either case, it is desirable to use a rubber gasket or the like to improve the sealing between the cylinder part 2 and the piston part 1 and prevent moisture from entering.In the case of a disposable tip, the piston part 1 should be made of rubber-like material. It is preferable that it be made of an elastic body and connected to the cylinder part 2 via a flange-like stopper to ensure airtightness.

Of the above two types, the syringe type is used in several doses, while the disposable tip type is used in one session.
Suitable for filling batches.

FIG. 3 shows how the disposable tip type syringe 5 is used. In other words, the syringe 5 is set in the extrusion device 6, which is a cylinder that has a hole at the tip and has a piston loosely fitted into the tip so that it can be inserted into the piston portion 1 of the syringe. It is.

〔effect〕

The restorative material of the present invention is a one-paste type that does not harden during storage, and is filled in a syringe, so unlike conventional two-part restorative materials, it requires the complicated operation of kneading the two parts with water just before use. (The paste whose viscosity has been adjusted in advance can be directly filled with a syringe, for example, into the root canal of a tooth.Then, the filled paste is hardened by hydroxyapatite due to moisture in the body.) generated.

As described above, the one-paste type restorative material of the present invention can significantly improve workability in use compared to conventional ones.

The one-paste type restorative material of the present invention can be used not only as a dental restorative material such as a root canal filling lining material, a covering material, a periodontal pocket filling material, and a filling material under tooth extraction, but also as a bone cement, bone filling material, etc. It can also be widely used in applications such as orthopedic repair materials.

〔Example〕

EXAMPLES Hereinafter, in order to explain the present invention more specifically, Examples will be shown, but the present invention is not limited to these Examples.

Example 1 CaHPO4, -2HzO was calcined at 500°C for 2 hours to obtain γ-CazP10r. This powder and CaCO3 powder were mixed at a ratio of 1:2 (molar ratio) and heated at 1400°C in air for 2 hours.
After firing for an hour, it was left to cool outside the furnace. It was confirmed from the X-ray diffraction pattern that the generated powder was tetracalcium phosphate.

This sample and CaHPO4 powder have a Ca/P molar ratio of 1.6.
The powder passed through a 200-mesh sieve and glycerin were mixed and kneaded at a ratio of 2:1 (weight ratio) to form a paste. The viscosity of this paste was 140 voids. This paste was filled into a polyethylene syringe (inner volume: 21R1) and a disposable tip (inner volume: 0.5 m), and the tips were capped to obtain a one-paste type repair material. Next, this was stored in a thermostat kept at 30°C for 3 months.

As a result, the viscosity of both pastes was 140 poise. Further, when the stored one-paste type restorative material was filled into the root canal of each extracted denture using a syringe and immersed in water at 37° C. for 24 hours, a good hardened hydroxyapatite body was obtained.

Furthermore, the paste was poured into a cylindrical mold with a diameter of 611 m and a height of 12 mm using a syringe, and both sides were covered with a water-permeable film (pore diameter: 0.45 μm) and placed in water at 37°C. Soaked.

The cured product taken out after 48 hours was confirmed to be hydroxyapatite from an X-ray diffraction diagram.

The compressive strength of this cured product was 65 kg/cot.

Example 2 Tetracalcium phosphate produced by the same method as Example 1 was
After being pulverized and mixed with CaHPO4 to a predetermined Ca/P molar ratio, the mixture passed through a 200 sieve sieve and was uniformly mixed and kneaded with the kneading solution shown below to form a paste.

1. Ethylene glycol 2. Polyethylene gelcol 400 3. Polypropylene glycol 10004, Peanut oil 5. Silicone oil (TSF-4 manufactured by Toshiba Shincone Co., Ltd.)
51-50) 6. Liquid paraffin (Moresco White P-55 manufactured by Matsumura Oil Research Institute) After putting these pastes into a syringe and capping them, they were stored in a thermostat at 30°C for 3 months. Paste viscosity was measured at the initial stage and after 3 months to examine storage stability. If the viscosity after 3 months fluctuates within ±2% compared to the initial viscosity, there is no problem with practical fastening and the shelf life is good. Furthermore, the cured product obtained in the same manner as in Example 1 was examined for product and compressive strength.

In addition, in the same manner as in Example 1, the root canal of an extracted denture was filled with a syringe, and it was examined whether a good cured product could be obtained. Those in which a good cured product was obtained were rated as ○, and those in which no good cured product was obtained were rated as ×. These results are shown in Table-1.

Example 3 Tetracalcium phosphate powder alone, α-tricalcium phosphate powder alone, or a mixture of tetracalcium phosphate powder and other calcium phosphate powder so that the Ca/P molar ratio was 1.67. Glycerin weight ratio 2:1
The mixture was mixed to form a paste. These pastes were filled into syringes in the same manner as in Example 2, and the storage stability, compressive strength, and cured product of the removable denture filling were examined in the same manner as in Example 1.

The results are shown in Table-2.

[Brief explanation of the drawing]

FIGS. 1 and 2 are cross-sectional views showing typical embodiments of the syringe used in the one-paste repair material of the present invention, and FIG. 3 is a perspective view showing the usage of the syringe shown in FIG. 2. ■...Piston part, 2...Cylinder part, 3...
paste, 4... cap, 5... syringe, 6...
...Extrusion device.

Claims (1)

[Claims] 1. From the group consisting of α-tricalcium phosphate powder, tetracalcium phosphate powder, or a mixture of tetracalcium phosphate powder and other calcium phosphate powder, and vegetable oil, polyhydric alcohol, polyalkylene glycol, silicone oil, and liquid paraffin. A one-paste type restorative material made by filling a syringe with at least one selected mixing liquid.