JPH09322905A - Orthodontic bracket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the propagation of intraoral bacteria and to suppress the occurrence of intraoral decalcification, caries and gingival hypertrophy by incorporating inorg. antimicrobial powder into a bracket for direct bonding which is orthodontic-clinically used. SOLUTION: The inorg. antimicrobial powder is uniformly compounded with polycarbonate, etc., which are the main resin component of the orthodontic bracket. As a result, the propagation of the intraoral bacteria is suppressed and the occurrence of the intraoral decalcification, caries and gingival hypertrophy is suppressed. The inorg. antimicrobial powder to be used is exemplified by powder formed by depositing a gaseous antimicrobial agent on an inorg. carrier. Zeolite is preferably used as the inorg. carrier. Antimicrobial zeolite powder holding an antimicrobial metal is preferably used as the antimicrobial component to be used at the time of producing the inorg. antimicrobial powder. The antimicrobial zeolite is formed by substituting ion exchangeable ions with ammonium ions and antimicrobial metal ions and preferably includes ions of silver, copper or zinc.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an antibacterial orthodontic bracket containing an antibacterial powder containing an antibacterial inorganic component such as silver.

2. Description of the Related Art Conventionally, most of the brackets for direct bonding that have been used in orthodontic clinic are metal brackets and resin brackets. However, the resin bracket may cause demineralization, caries or gingival overgrowth on the surface of the bracket depending on the oral environment. It is reported that this is because the microbial flora in the mouth changes when the bracket is attached.

[0002]

Organic agents such as chlorhexidine have been used as dental disinfectants for oral bacteria, but application of these agents to orthodontic brackets makes it difficult to add because of the liquid form. There was a problem that the persistent antibacterial effect could not be corrected. In addition, the resin component of the orthodontic bracket may be deteriorated or the surface shape may be lost due to bacterial growth. Therefore, there is a high possibility that the decalcification, caries and gingival overgrowth in the mouth will be further aggravated.

[0003]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies in view of the above problems, and as a result, by uniformly blending an inorganic antibacterial agent powder with polycarbonate, which is a main resin component of a bracket for straightening, Suppress the growth of oral bacteria,
The present inventors have found that demineralization, caries and gingival overgrowth can be suppressed in the mouth, and have completed the present invention. The present invention provides a straightening bracket containing an inorganic antibacterial agent powder.

[0004]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. As the inorganic antibacterial agent powder used in the present invention, solid,
Examples of the powder include a liquid or gaseous antibacterial agent supported on an inorganic carrier. Examples of the inorganic carrier include crystalline aluminosilicate (hereinafter referred to as “zeolite”), amorphous aluminosilicate (hereinafter referred to as “AAS”), silica gel, activated amylna, diatomaceous earth, activated carbon, zirconium phosphate, hydroxyapatite, Although calcium oxide, magnesium oxide, calcium sulfate and the like can be mentioned, it is preferable to use zeolite having high chemical stability.

The antibacterial component used in the production of the inorganic antibacterial powder in the present invention may be in the form of solid, liquid or gas, such as silver, copper, zinc, mercury, lead,
Examples include metal ions such as tin, bismuth, cadmium, and thallium and their compounds, halogenated compounds such as stabilized chlorine, chloramine, and ethylene iodide, guanidines, thiazoles, quaternary ammonium salts, and thiocarbamates. However, because of its strong antibacterial activity, low solubility in water, long-lasting effect, and excellent safety for human body, antibacterial zeolite powder that holds antibacterial metal such as silver, copper, zinc, etc. Is preferably used.

As the zeolite in the present invention, both natural zeolite and synthetic zeolite can be used. Zeolite is generally an aluminosilicate having a three-dimensional skeleton structure, and has a general formula of xM _{2 / n} O · Al ₂
Is displayed in _{O 3 · ySiO 2 · zH 2} O. Here, M represents an ion-exchangeable ion and is usually a monovalent or divalent metal ion. n is the valence of the (metal) ion.
x and y are the coefficients of metal oxide and silica, respectively, z
Indicates the number of crystal waters. Specific examples of the zeolite include, for example, A-type zeolite, X-type zeolite,
Examples thereof include Y-type zeolite, T-type zeolite, high silica zeolite, sodalite, mordenite, analcime, clinoptilolite, chabazite and erionite. However, it is not limited to these. The ion exchange capacities of these exemplified zeolites are A-
Type zeolite 7meq / g, X-type zeolite 6.4meq / g, Y-
Type zeolite 5meq / g, T-type zeolite 3.4meq / g, sodalite 11.5meq / g, mordenite 2.6meq / g, analcime 5meq / g, clinoptilolite 2.6meq / g, chabazite 5meq / g, erionite It is 3.8 meq / g, and each has a sufficient capacity for ion exchange with antibacterial metal ions.

The antibacterial zeolite used in the present invention is an ion-exchangeable ion in the above-mentioned zeolite, such as sodium ion, calcium ion, potassium ion, magnesium ion, iron ion, etc. It is preferably substituted with ammonium ions and antibacterial metal ions. Examples of antibacterial metal ions include silver, copper, zinc, mercury, tin, lead, bismuth,
Mention may be made of cadmium, chromium or thallium ions, preferably silver, copper or zinc ions. From the viewpoint of antibacterial property, the antibacterial metal ion is 0.
It is appropriate that the content is 1 to 15% (% by weight, the same applies hereinafter unless otherwise specified). Silver ion 0.
1 to 15% and copper ion or zinc ion or tin ion
The antibacterial zeolite containing 0.1 to 18% is more preferable. Further, by further exchanging ammonium ions to the antibacterial zeolite by 1.5 to 5.0%, deterioration of the resin component of the added orthodontic bracket over time is prevented,
Further, the antibacterial property can be maintained for a long period of time.
In the present specification,% means weight% on a 110 ° C. dry basis.

The method for producing the antibacterial zeolite used in the present invention will be described below. The antibacterial zeolite used in the present invention is, for example, an antibacterial metal ion such as a silver ion prepared in advance, preferably by bringing the zeolite into contact with a mixed aqueous solution containing an ammonium ion, and the ion-exchangeable ions in the zeolite as described above. Replaces ions. The contact can be performed at 10 to 70 ° C., preferably 40 to 60 ° C. for 3 to 24 hours, preferably 10 to 24 hours by a batch system or a continuous system (for example, a column method). The pH of the mixed aqueous solution is 3 to 10, preferably 5
Adjusting to ~ 7 is appropriate. By this adjustment, it is possible to prevent silver oxide or the like from depositing on the zeolite surface or in the pores. Also, each ion in the mixed aqueous solution is
Usually, both are supplied as salt. For example, silver ion is
Copper ions such as silver nitrate, silver sulfate, silver perchlorate, silver acetate, diammine silver nitrate, and diammine silver sulfate are copper nitrate (I
I), copper sulfate, copper perchlorate, copper acetate, potassium tetracyanocuprate, etc., zinc ion is zinc nitrate (II), zinc sulfate, zinc perchlorate, zinc thiocyanate, zinc acetate, etc., ammonium ion is Ammonium nitrate, ammonium sulfate, ammonium acetate, ammonium perchlorate, ammonium thiosulfate, ammonium phosphate and the like can be used.

The content of silver ions and the like in the zeolite can be appropriately controlled by adjusting the concentration of each ion (salt) in the mixed solution. For example, when the antibacterial zeolite contains silver ions and zinc ions, the silver ion concentration in the mixed aqueous solution is 0.002 M / l to 0.15 M /
1 and the zinc ion concentration of 0.15 M / l to 2.8 M / l, an antibacterial zeolite having a silver ion content of 0.1 to 15% and a zinc ion content of 0.1 to 18% is appropriately prepared. Obtainable. When the antibacterial zeolite further contains copper ions and ammonium ions, the copper ion concentration in the mixed aqueous solution is 0.1 M / l to 2.3 M / l, and the ammonium ion concentration is 0.9 M / l to 2. By adjusting the amount to 8 M / l, an antibacterial zeolite having a copper ion content of 0.1 to 18% and an ammonium ion content of 1.5 to 5.0% can be obtained.

In the present invention, an ion exchange can also be carried out by using an aqueous solution containing each ion alone in addition to the mixed aqueous solution as described above and sequentially bringing the respective aqueous solutions into contact with zeolite. The concentration of each ion in each aqueous solution can be determined according to the concentration of each ion in the mixed aqueous solution. The zeolite after the ion exchange is thoroughly washed with water and then dried. Drying at normal pressure 105 ℃ ～ 1
It is preferably carried out at 15 ° C. or 70 to 90 ° C. under reduced pressure (1 to 30 torr).

The orthodontic bracket of the present invention can be easily prepared by incorporating an inorganic antibacterial agent powder into a commercially available orthodontic bracket. That is, the inorganic antibacterial agent powder may be mixed with the resin component of the orthodontic bracket to be molded so that at least a part of the inorganic antibacterial agent powder is exposed on the surface portion. In order to uniformly disperse and mix in the resin, the particle size of the inorganic antibacterial agent powder is 0.5 to 7.5 μm.
It is preferred that Inorganic antibacterial agent powder is preferably added to the orthodontic bracket of the present invention in an amount of 0.5 to 8.0% by weight, more preferably 0.5 to 3.0% by weight.

The orthodontic bracket of the present invention has the effects of suppressing the growth of bacteria in the mouth and suppressing the occurrence of decalcification, caries and gingival overgrowth.

[0012]

EXAMPLES The present invention will now be described in more detail with reference to examples. Reference Example (Preparation of Inorganic Antibacterial Agent Powder) Commercially available A-type zeolite powder (Na ₂ O · Al ₂ O ₃ ·
1.9SiO ₂ · xH ₂ O: average particle size 1.5 μm) and amorphous aluminosilicate powder (0.9Na ₂ O.Al ₂ O ₃ .2.4S) synthesized according to JP-A-61-174111.
Inorganic antibacterial agent containing silver, zinc and copper using iO ₂ · xH ₂ O: average particle size 0.9 μm, zirconium phosphate (average particle size 0.5 μm), hydroxyapatite (average particle size 3.2 μm) A powder was prepared. Table 1 shows the contents of metals and the like.

[0013]

[Table 1] ─────────────────────────────────── No. Types of inorganic carriers Metal and other ion contents (wt%) A A- type zeolite _{Ag: 0.7, NH 4: 4.3} B A- type zeolite Ag: 2.0, Zn: 13.1, NH 4: 3.1 C A- type zeolite Ag : 2.0 D AAS Ag: 7.5, NH 4: 1.7 E zirconium phosphate _{Ag: 1.1, NH 4: 1.9} F hydroxyapatite Ag: 1.2, NH _4: 1.5

Example (Preparation of Orthodontic Bracket Test Specimen) A commercially available polycarbonate resin was mixed with a predetermined amount of the inorganic antibacterial agent powder prepared in Reference Example to prepare a plate specimen of 50 × 50 × 2-5 mm. did. As a comparative example, a product containing no inorganic antibacterial agent powder was similarly prepared. The blending amount is shown in Table 2. Test Example 1 (Antibacterial test) Examples and of oral bacteria Miu chest bacterial solution on the orthodontic bracket test pieces prepared in Comparative Example (the number of initial bacteria 8 × 10 ⁴
Cells / ml) and the antibacterial performance was tested based on the viable cell count after 24 hours. Table 2 shows the results. Test Example 2 (deterioration test) In order to evaluate the deterioration with time of the bracket test piece for orthodontics in an accelerated test, the test piece was immersed in a denture cleaning solution and tested. Orthodontic bracket test pieces prepared in Examples and Comparative Examples were treated with an alkaline peroxide denture cleaner (Reckitt & Colman) and a neutral peroxide-enzyme denture cleaner (Lioden manufactured by Lion).
It was immersed in each solution of t) at room temperature for 10 days. It was taken out every two days, washed with water, and immersed again. After 10 days, the degree of deterioration of the surface was observed with a scanning electron microscope (SEM) and evaluated according to the following criteria. Table 2 shows the results. (Judgment criteria)-: No change ±: Slightly changed +: Slightly changed ++: Changed +++: Significantly changed

[0015]

[Table 2] ─────────────────────────────────── No. Inorganic antibacterial agent powder molded product Antibacterial test result Deterioration test result No. Blending amount (wt%) Color (Number of bacteria after 24 hours) Alkaline liquid Neutral liquid Example 1 A 1.0 White 0 − − Example 2 B 0 .5 white 0 --- Example 3 B 2.5 white 0 ---- Example 4 B 7.2 light yellow 0 ---- Example 5 C 1.0 light brown 0 ± -Example 6 D 1.2 white 0- -Example 7 E2.5 White 0 --- Example 8 F 1.3 White 0 --- Comparative Example-0 White 8 × 10 ⁴ ++ ±

Claims (3)

[Claims] 1. A straightening bracket containing an inorganic antibacterial agent powder. 2. The orthodontic bracket according to claim 1, wherein the inorganic antibacterial agent powder contains at least one of silver, copper and zinc. 3. The orthodontic bracket according to claim 1, wherein the inorganic antibacterial agent powder contains at least one of silver, copper and zinc and ammonium ions.