JPS6219508A - Root canal filling material for dental use - Google Patents

Abstract

PURPOSE:To provide the titled filling material free from irritation to living body and curable within a relatively short time to a hardened material having moderate hardness, and composed of a powdery agent containing alpha-type tricalcium phosphate, hydroxyapatite, an X-ray contrasting material, an antibacterial material or a drug-active material, and a liquid polyacrylic acid. CONSTITUTION:The objective filling material is composed of (A) a powdery agent containing (i) 10-90% alpha-type tricalcium phosphate (alpha-TCP), (ii) 9-70% hydroxyapatite (HAP) and (iii) 1-30% (in total) X-ray contrasting material and an antibacterial material or a drug-active material and (B) a liquid polyacrylic acid reactive with said powdery agent and forming a coagulated and hardened material in the oral cavity. alpha-TCP is a bio-compatible inorganic material having chemical activity and convertible to HAP in the presence of water, and an excellent material for filling in root canal can be produced by compounding the compound with HAP at a proper ratio. The filling material can be hardened in the oral cavity in a relatively short but sufficiently long time to allow the operation, while maintaining the affinity to living body.

Description

[Detailed description of the invention] industrial 1 The present invention relates to a dental root canal filling material.

[So-called powder-type dental compositions using L1 quality powder and liquid are applied in many fields in various materials, including tooth restoration materials, pulp covering materials, root canal filling materials, and various dental materials. Cement (for bonding, filling, covering, lining, backing, etc.) is a typical example.

The amounts of these materials are mainly (and main components) of inorganic substances or synthetic resins, but the problem that has traditionally been raised is their harmful effects on living organisms. In other words, conventional dental compositions are irritating to living organisms in some way, and since they are made of materials that are specific to living organisms, they can be said to have poor affinity.

For this reason, when conventional dental compositions are used as root canal filling materials, they are irritating to living organisms and are difficult to use. It has been desired to develop a dental root canal filling material "I" which can harden firmly in a short amount of time.

1 This invention is a dental root canal filling that can be cured with appropriate strength in a relatively short period of time with an appropriate operational margin while not irritating the living body and ensuring compatibility with the living body. The purpose is to provide materials.

11 animals LL In order to achieve the above object, this invention uses α-TCP (
α-Ca 3 (POa) 2 : alpha-type tricalcium phosphate), hydroxyapatite, an X-ray contrast material, and reacts with this powder in the oral environment to solidify and harden. The gist of this paper is a dental root filling material consisting of a polyacrylic acid-based liquid agent that can be used as a commercially available product.

<2-TCP (α-Ca3(PO4)2: alpha-type tricalcium phosphate), hydroxyapatite,
A powder containing an X-ray contrast material and at least one of an antibacterial material or a medicinal material is mixed with a polyacrylic acid-based liquid that can react with the powder in the oral cavity environment to form a solidified product.

The greatest feature of this invention is that α-TCP is used as a component of the powder.

As is well known, the main component constituting inorganic components such as tooth substance and bone is HAP (Ca + o (PO4)s (O
H)2: Hydroxyapatite), but inorganic biomaterials similar to this have recently attracted attention.

The reason for this is said to be that in addition to its in-vivo stability, it has compatibility with living tissues, such as leading to the formation and bonding of new bone at the interface with hard tissues. These substances are classified into biologically inert substances such as A11203 and bioactive substances such as A-IAP based on the difference in their activity with the biological tissue interface. α-TCP in the present invention is originally similar to low-crystalline HAP,
Although it is a HAP precursor that is biodigradable, it also has chemical activity and is a biocompatible inorganic material that can be expected to be converted to HAP in the presence of water.

By kneading this α-TCP with a polyacrylic acid-based liquid, it is possible to form a solid solidified product in the oral cavity in a short time. It is a well-known fact that polyacrylic acid copolymers are widely and generally used as liquid components of dental cement compositions.

As the biocompatible inorganic material, α-T in this invention
In addition to CP, there are also the above-mentioned HAP1 and β-TCP,
Both HAP and β-TCP have low chemical activity and are difficult to cure in the oral environment. This is the meaning of using α-TCP as a component, and by combining it with HAP in an appropriate composition, it can be used as a new, unprecedented root canal filling material.

By using a polyacrylic acid-based aqueous solution as the liquid agent, it is possible to impart appropriate viscosity to the kneaded mud, and to allow firm hardening in the oral cavity environment in a relatively short period of time while providing an appropriate operational margin.

Root canal filling materials are used to fill in material defects in the pulp cavity that occur after root canal repair or treatment of infected root canals with an appropriate material. Root canal treatment ends when the root canal is properly filled.

The purpose is to completely close the cavity in the root canal,
By blocking the infection route between the root canal and the periodontal tissue, between the root canal and the oral cavity, and by roughly protecting the apical wound and forming granulation tissue, which leads to the healing of bone scars, The aim is to preserve pulp teeth as something harmless to the human body and to continue the function of the teeth.

Conventionally, root canal filling materials based on Ca(O)-1)z have been most commonly used in this field, but these have a therapeutic effect as their primary purpose and are often non-hardening. Moreover, conventional root canal filling materials are used in combination with gutta-percha to fill root canals, but this procedure is complicated.

Therefore, if the dental root canal filling material of the present invention is used, airtight filling can be completed in just one operation, and the material can solidify and harden in a short period of time within the root canal with an appropriate operating margin. It is an extremely advantageous material. Of course, conventional solid material combination methods are also possible.

The root canal filling material of this invention is made from the powder and liquid agents shown in Table 1.

First, the powder will be explained. The powder is α-TCP, 1-
It contains the following components: IAP, an X-ray contrast agent, and a small amount of either an antibacterial agent or a medicinal agent.

The powder contains 10 to 90% α-TCP.

If the α-TCP content is less than 10%, the affinity for living organisms will decrease, and not only will the curing time become longer, but the coagulation will not proceed completely.

On the other hand, if α-TCP is more than 90%, it is advantageous in terms of affinity for living organisms, but in terms of physical properties, the curing reaction proceeds quickly, which not only makes it difficult to obtain an appropriate operating time, but also causes the coagulation and hardening of the product. strength becomes too high.

The root snow filler only needs to fill the voids in the root canal, and if the hardening strength is too high, it will not be able to be removed during retreatment.

Next, HAP has the primary purpose of improving biocompatibility,
It is used to adjust the reaction between α-TCP and polyacrylic acid and to adjust (lower) the strength of the solidified and cured product.

HAP is 9 to 70 in powder depending on the content of α-TCP.
%included. If HAP is less than 9%, the above objectives cannot be achieved, and in particular, the strength of the powder becomes too high, making it impossible to improve biocompatibility. Also, if HAP is more than 70%,
Biocompatibility improves, but the solidified and cured product becomes difficult to react with liquid agents in a short period of time.

X-ray contrast materials, antibacterial materials, or medicinal materials include iodoform, barium sulfate, tank powder, silver powder, bismuth subcarbonate, various salts of chlorhexidine, calcium fluoride, sodium monofluorophosphate, etc. Iodobolum has both X-ray contrast and antibacterial functions. Barium sulfate can be used as an Xta contrast agent, but when barium sulfate alone is used, other ingredients such as chlorhexidine hydrochloride must be added as an antimicrobial agent. Sodium monofluorophosphate can be used as a medicinal agent.

The X-ray contrast material, antibacterial material, or medicinal material is contained in the powder in a total amount of 1 to 30% depending on the usage situation.

If the amount of X-ray contrast material, antibacterial material, or medicinal material is less than 1%, X-ray opacity will be insufficient, and it will be difficult to check the filling condition in the root canal after application. It becomes impossible to maintain the condition. Photographs cannot be taken, resulting in bacterial infection. Further, even if the amount of the X-ray contrast material, antibacterial material, or medicinal material exceeds 30%, no effect other than fulfilling its function can be obtained, and furthermore, the contents of α-TCP and HAP will be relatively reduced, which is not preferable.

Next, the polyacrylic acid-based liquid agent will be explained with reference to Table 1.

The liquid agent contains polyacrylic acid, purified water, organic acid or inorganic acid, and other components.

As the polyacrylic acid, acrylic acid and itaconic acid copolymers, acrylic acid and fumaric acid copolymers, acrylic acid and maleic acid copolymers, etc. can be employed.

Polyacrylic acid is contained in the solution in an amount of 10 to 40%. If the polyacrylic acid content is less than 10%, the curing reaction with the powder will not proceed sufficiently, and if it is more than 40%, the viscosity of the liquid will increase, the kneaded mud will become too hard, and the operability will decrease. Difficult to use when filling tubes.

When the amount of purified water is less than 35%, the viscosity of the kneaded mud becomes too high to be used, and conversion of α-TCP to HAP cannot be expected. If the purified water is more than 88.5%, the viscosity will be too low and it will be difficult to use.

The organic acid or inorganic acid is mainly a monobasic or polybasic carboxylic acid such as glycolic acid, lactic acid, citric acid, acetic acid, tartaric acid, etc. or an inorganic acid such as phosphoric acid, hydrochloric acid, nitric acid, etc. Contains 15%. These are for adjusting curing time, curing sharpness and curing strength. Here, the sharpness of curing refers to the rising speed at which the kneaded mixture of powder agent and liquid agent quickly hardens after a certain operating margin time has elapsed.

If the organic acid or IM-free content is less than 1%, the above objective cannot be achieved, and if it is more than 15%, the operating time becomes extremely short and sufficient kneading becomes impossible, resulting in a completely cured product. This leads to disadvantages such as difficulty forming aggregates and causing brittle fracture.

Other ingredients include water-soluble calcium salts, aluminum salts,
sodium salt, magnesium salt, cationic surfactant,
Anionic surfactants, nonionic surfactants, sodium hydroxide, calcium hydroxide, carboxymethyl cellulose, hydroxypropyl cellulose, polyoxyethylene high polymers, polyethylene glycol, water-soluble silicones, etc. Contains 5-10%. The water-soluble calcium salt is preferably a phosphate, such as calcium dihydrogen phosphate, which is used to adjust curing time, sharpness of curing, and mechanical strength.

The surfactant is used to ensure the wettability of the mixed mud. The PH adjusting material adjusts PI-1.

Thickeners adjust viscosity.

In any case, the proportions of each component in the powder and the proportions of each component in the liquid are adjusted as appropriate depending on the purpose.

Maru i1 Next, Table 2 shows examples of root canal filling agents.

In Example 1, the powder-liquid ratio was 1.0 and the curing time was 45 minutes.
The compressive strength is 75 K Of/cm2. Example 2
has a powder/liquid ratio of 1.0, a curing time of 35 minutes, and a compressive strength of 93 K of/cm2. In Example 3, the powder-liquid ratio was 1.0, the curing time was 60 minutes, and the compressive strength was 88.
kgf/cm2.

In Examples 1, 2, and 3, the curing time is appropriate as the operating margin time for the root canal filling material, and the compressive strength is 19, which is appropriate.

When actually using the ground snow filler, a powder agent and a polyacrylic acid-based liquid agent are kneaded into a slurry at a predetermined powder-liquid ratio, for example 1.0, to provide an appropriate viscosity. If the kneaded mud is filled, for example, into a root canal after repair, it will solidify and harden with appropriate compressive strength after a predetermined hardening time.

Since this solidified and cured product contains α-TCP and HAP, it has an affinity for living organisms and does not stimulate living organisms.

By the way, in this invention, a polyacrylic acid-based liquid agent is used. It has been revealed that if a lactic acid polymer-based liquid agent is used instead of a polyacrylic acid-based liquid, the compressive strength of the set and cured product will decrease and the curing time will become longer.
Lactic acid polymer liquids are not suitable for use.

As is clear from the above, according to the present invention, when used as a root canal filling material, it can be used as a root canal filling material without irritating the living body and while ensuring compatibility with the living body. It can be cured with appropriate strength in a relatively short period of time with some operating time.

Claims (1)

[Claims] α-TCP (α-Ca_3(PO_4)_2; alpha-type tricalcium phosphate), hydroxyapatite, X
A dental root canal filling material comprising a powder containing a linear contrast material and at least one of an antibacterial material or a medicinal material, and a polyacrylic acid-based liquid that reacts with the powder in the oral cavity environment to form a solidified and hardened product.