JPH07265337A - Bioabsorbable protective film and manufacture thereof - Google Patents

Abstract

PURPOSE:To promote the regeneration and renewal of a bone by a method wherein a film to be implanted into a bone lost part or a part requiring renewal of a periodontium is made up of a felt made of a bioabsorbable material to prevent the infiltration of a gum bond tissue-oriented cell and an epithelial cell into an affected part and allows assistance in the induction of an osteoblast. CONSTITUTION:To induce (proliferate) a bone, a film to be implanted into a bone lost part or a part requiring the renewal of a bone of a periodontium is made up of a felt made of a bioabsorbable material and the bioapsorbable material comprises a polymer of glycolic acid or a copolymer of lactic acid and glycolic acid. The degree of polymerization of the copolymer is in a range of 2000-5000 and the felt is formed by compressing fibers with the fineness of 2.0-4.0 denier. In the production, the bioabsorbable material is melted to be spun and drawn to make fibers, which undergoes a heat treatment to be knitted and then, is formed into a felt by compressing. A film thus obtained is pressed thermally.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an implant article used for a periodontal tissue-guided regeneration (GTR) method in the periodontology field, and more particularly to a protective film formed from a bioabsorbable material for the implant article. Regarding

[0002]

2. Description of the Related Art In wound healing after surgery in periodontology, the healing speed of gingival connective tissue cells and epithelial cells is faster than that of osteoblasts.
h occurs, and it becomes difficult to obtain bone regeneration / new birth. For this reason, the GTR method has recently received attention in the periodontology field, and its effectiveness in bone regeneration and bone renewal for a bone defect site has been recognized. The basic concept is to prevent the invasion of gingival connective tissue cells and epithelial cells into the affected area by using a semipermeable membrane, and to promote the induction of osteoblasts, thereby achieving regeneration / renewal of bone. For this purpose, conventionally, a semi-permeable membrane such as a tetrafluoroethylene resin (PTFE) membrane or a Millipore filter has been used to secure a void for bone formation and enable bone regeneration. However, since these protective films are non-absorbable in vivo, they must be removed after surgery, and since they do not adhere to biological tissues (gingival periosteal flap, etc.), there is the drawback that postoperative sutures tend to be cleaved. It was In order to compensate for the defects of the protective film, a collagen film, a polylactic acid film,
Clinical applications have been made using biodegradable membranes such as oxidized cellulose membranes and chitosan membranes. There is a problem in strength that can secure the voids, and it has not yet been put to practical use.

[0003]

The object of the present invention is to prevent the invasion of gingival connective tissue cells and epithelial cells into the affected area by applying to the defect site of bone and the like, and to assist the induction of osteoblasts. Bioresorbability that facilitates surgery and does not require post-surgery removal by promoting bone regeneration / renewal and imparting appropriate biodegradation (bioabsorption) period, hardness, and strength, and good biocompatibility. It is to provide a protective film. Another object of the present invention is to provide a method for producing such a protective film.

[0004]

SUMMARY OF THE INVENTION In the present invention, the above problems are solved by applying a bioabsorbable felt material. That is, the present invention is a membrane that is implanted in a periodontal tissue in a bone defect site or a site in which bone renewal is necessary in order to cause bone induction (proliferation), and the membrane is made of a felt formed of a bioabsorbable material. Is a protective film. In addition, the bioabsorbable protective film of the present invention is formed by melt-spinning a bioabsorbable material, stretching it into fibers, heat treating the fibers, braiding the fibers and then crimping them to form a felt-like film. Process,
Manufactured by a method comprising the step of hot pressing the membrane.

[0005]

In the present invention, by forming the bioabsorbable material into a felt shape, a protective film having an appropriate decomposition (bioabsorption) period and an appropriate hardness and strength for the operation can be obtained. By using the protective film, it becomes possible to protect the affected area for a certain period without performing postoperative removal treatment.

[0006]

EXAMPLE As a bioabsorbable polymer in the present invention,
For example, lactic acid, glycolic acid, β-hydroxybutylcarboxylic acid, β-propiolactone, γ-butyrolactone,
Examples thereof include homopolymers and copolymers obtained from γ-valero-3-methylbutyrolactone, δ-valerolactone, ε-caprolactone. By selecting an appropriate bioabsorbable material among these, and by selecting the degree of polymerization of the polymer and the thickness of the felt fiber, it has an appropriate decomposition (bioabsorption) period, hardness and strength. A protective film is obtained. Furthermore, by selecting the manufacturing conditions of the bioabsorbable protective film, it becomes possible to form a protective film having more appropriate above-mentioned properties. For example, a bioabsorbable polymer has a degree of polymerization of 2,000 to 5,000 glycolic acid or glyco-
It is selected from the copolymers of acid and lactic acid and has a thickness of 2.0-
By selecting a felt formed by crimping 4.0 denier fibers, a suitable decomposition (bioabsorption) period, hardness, and
A bioabsorbable protective film having strength can be obtained. Further, fibers produced from a bioabsorbable material by melt spinning or drawing are heat-treated at a temperature of 90 to 120 ° C. for 1 to 4 hours, or a treatment temperature of 90 to 1 in the step of hot pressing the membrane.
By performing hot pressing at a temperature of 20 ° C. for a treatment time of 0.5 to 10 minutes, it is possible to obtain a material having a more suitable decomposition (bioabsorption) period, hardness and strength. Further, in the step of forming a felt-like film by pressure bonding, a synthetic felt is knitted into two or more layers and nidle punched to obtain a felt film with no visible stitches. It also prevents fuzz and fraying of the membrane. In order to obtain a more appropriate hardness, it is effective to perform the hot pressing twice. Example 1 Polyglycolic acid was dissolved in a solvent prepared by mixing 10 parts by weight of phenol and 7 parts by weight of trichlorophenol.
After heating at 0 ° C for 3 minutes and cooling, the intrinsic viscosity (ηsp /
c) of 1.5 was obtained. The obtained polyglycolic acid chips were melt-spun at 245 ° C. and stretched to obtain 12 denier 35 denier yarns. After heat-treating this fiber at 106 ° C. for 3 hours, it was made into a tube-shaped knit by a cylinder knitting machine. A quadruple layer of this knit is niddle punched to form a non-woven fabric whose stitches are almost invisible, and this non-woven fabric is hot-pressed at 100 ° C. for 5 minutes to prevent fuzzing and fraying, and to provide a uniform distribution. A felt-like material having elongation was constructed. This material is 15mm x 20
It was cut into a mm-sized oval shape and subjected to ethylene oxide gas sterilization. 2 in accordance with the conventional method for bone defect or bone deficiency
When implanting a round implant, the sterilized felt-like protective film obtained above was used for 18 sites in 12 cases for GTR.
Went the law. When the gingival periosteal flap was peeled off and observed at the time of secondary surgery, bone regeneration was observed in 16 out of 18 sites. Example 2 In order to impart an appropriate hardness to the protective film, the felt-like material produced by the same process as in Example 1 was further subjected to 3 ° C. at 120 ° C.
After hot pressing again for 0 seconds, it was cut into an oval shape with a size of 15 mm × 20 mm and sterilized with ethylene oxide gas. When a double implant was implanted using the protective film during the GTR operation, it had an appropriate hardness and was excellent in operability, and sufficient voids for bone formation could be secured.

[0007]

INDUSTRIAL APPLICABILITY The protective film of the present invention prevents the invasion of gingival connective tissue cells and epithelial cells into the affected area during the GTR method after surgery in the periodontology region and prevents osteoblastic cells from invading. In addition to promoting induction and promoting bone regeneration / new birth, it has an appropriate decomposition (bioabsorption) period, hardness, and strength, making it easy to perform surgery, and there is no need to remove the protective film after surgery.

Claims (12)

[Claims] 1. A membrane which is implanted in a periodontal tissue at a bone defect site or a site where osteogenesis is required in order to induce bone induction (proliferation), and the membrane is made of a felt made of a bioabsorbable material. A protective film which is characterized in that 2. The protective film according to claim 1, wherein the bioabsorbable material is a polymer of glycolic acid. 3. The protective film according to claim 1, wherein the bioabsorbable material is a copolymer of lactic acid and glycolic acid. 4. The degree of polymerization of the polymer is 2,000 to 5,000.
The protective film according to claim 2 or 3, which is in the range of. 5. The felt is formed by press-bonding fibers having a thickness of 2.0 to 4.0 denier.
The protective film described. 6. A method for producing a bioabsorbable protective film according to claim 1, wherein the bioabsorbable material is melt-spun and stretched into fibers, the heat treatment of the fibers, and the knitting of the fibers. After that, it is pressure-bonded to form a felt-like film,
A method for producing a protective film, comprising the step of hot pressing the film. 7. A bioabsorbable material having a degree of polymerization of 2,000 to 5,
7. The method according to claim 6, which comprises 000 polyglycolic acid or a copolymer of lactic acid and glycolic acid. 8. The thickness of the bioabsorbable fiber to be heat treated is 2.
The method according to claim 6 or 7, wherein the denier is 0 to 4.0. 9. The conditions for heat-treating the bioabsorbable fiber include:
The manufacturing method according to claim 6, 7 or 8, wherein the heat treatment temperature is in the range of 90 to 120 ° C, and the heat treatment time is in the range of 1 to 4 hours. 10. The method according to claim 6, wherein the step of pressure-bonding the bioabsorbable fiber comprises knitting the fiber, stacking the fibers in a double layer or more, and punching with a needle punch. 11. The hot press condition is a processing temperature of 90 to 120.
The production method according to claim 6, 7, 8, 9 or 10, wherein the treatment time is in the range of 0 ° C and the treatment time is in the range of 0.5 to 10 minutes. 12. The manufacturing method according to claim 6, 7, 8, 9, 10 or 11, wherein the step of hot pressing comprises two steps.