JPS59500453A - polymer acrylic prosthesis - 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] polymer acrylic prosthesis Technical field The present invention is an artificial bone or hard tissue substitute used as a bone or hard tissue substitute in any part of the body. Concerning organs. More specifically, the present invention provides biocompatible and bone- and bone- A porous implant is disclosed that promotes tissue growth and attachment.

Background technology All teeth/roots, bone or hard tissue or defective parts must be replaced or repaired. If not, biological compatibility and adequate growth and attachment of surrounding body tissues and bones. Availability must be ensured. Filed on December 8, 1980 by Bruin et al. and assigned to Medical Biological Sciences, Inc. (assignee of this invention). No. 214,572 was modified with a small amount of barium sulfate and Physically co-coating with Droxyethyl methacrylate (PHEMA) A selected and sized polyethyl methacrylate (PMMA) bonded to ) improve compatibility and tissue structure by providing a prosthetic device comprising beads; The chief is working on these issues. PMMA particles coated with PI (EMA) The bond obtained between the Give evidence. Hydrophilic, with appropriate bone and tissue ingrowth moistened by body fluids This is ensured by the use of PHEMA coating.

Summary of the invention The invention consists of an assembly of modified PMMA beads that are not initially glued together. Provide tools. In the present invention, in particular, [Modified J] PMMA beads are PHE Individual pieces of bulk coated with MA and further modified with barium sulfate for X-ray identification. shall mean beads.

Loose, individual modified PMMA beads are loaded into bone defect areas, e.g. depressions. or into hard tissue parts of the body that are intended for repair, reconstruction or replacement.

Areas where loose, individual modified PMMA beads are used include e.g. Third molar alveolus where teeth are not desired; bifurcations between adjacent roots or bony depressions as well as combs and It is caused by diseases of the bones and bones and involves subosseous cavities. For parenteral applications, bone fracture treatment, bone cancer repair, bone reinforcement in plastic surgery, filling of defective bone areas and Includes replacements for metal implants as well as replacements for metal implants with drawbacks .

Detailed description of the invention The prosthesis of the present invention does not contain modified PMMA beads, but in individual discrete form. This bead, found in Type 3, is used to transport silver amalgam, for example. Fill the depression or other area of hard tissue defect or disease using a dental instrument such as Ru. When the hard tissue void is completely filled with discrete individual modified PMMA beads When assembled, the surrounding soft tissue is sutured over the bead to completely surround the bead. one time Once surrounded, the beads are in contact with each other and easily wetted by blood and body fluids. form a hole that can be penetrated. In this way, bone growth is promoted and bone depression is prevented. It will be done. As the treatment process progresses, bone and/or tissue Ingrowth around the formation of a prosthesis comprising an assembly of modified PMMA beads leading to.

Loose non-woven fabric coated with PHEMA and modified with small particle barium sulfate. The conjugated PMMA beads are described in Applicant's patents, which are incorporated herein by reference. Similar to the method disclosed in Application No. 214,572 (filed on December 8, 1980) Manufactured by law. Implant relative to prevent PMMA bead binding Barium sulfate content increases while PI (EMAO content decreases and pressure is avoided) Ru. Agglomerates formed by coated PRMA particles can be removed by physical means, e.g. crushed in a mortar and pestle.

Discrete unbonded modified PMMA beads comprising hard tissue implants of the present invention The product is manufactured according to the following method. PMMA beads are 0.7 micron or 1 micron. about 10 to 20 volumes of barium sulfate, preferably 10%, of particle size less than , and about 215 to 43% by weight. PMMA bead size The size is preferably chosen with a view to pore size development promoting bone growth. Book Under various embodiments of the invention, the PMMA beads have a mesh size of about 20 to 24. particle size (approximately 700 to 840 microns in diameter) or approximately 24 to 30 microns in diameter This mesh size (particle diameter approximately 590-700 microns) are most easily transported and can also fill voids within hard tissue areas, further promoting bone growth. Forms the size of the hole as it progresses. PMMA contains small amounts of plasticizers or comonomers. obtain.

Monomeric hydroxyethyl methacrylate (HEMA) about 4-7% by weight, preferably or 5% by weight (based on PMMA), then PMMA beads-barium sulfate mixture. mix the entire mixture thoroughly and then combine to homogenize the PMMA beads. Provide uniform coaching. I (EMA is of high purity, with a minimum value of approximately 984% and a trace amount Polymerization is facilitated by inhibitors such as methyl ester of hydroquinone (MEHQ). suppressed. HEMA is a crosslinker such as triethylene di-1-cocol dimethacrylate. Preferably modified by the addition of a bridging agent, the triethylene glycol dimethacrylate The composition contains about 1-5% HEMA, preferably 5%.

The mixed PMMA beads are placed in silicone rubber molds or in Teflon, polyethylene molds. or approximately 716 inches to 1/8 inch thick on a non-polar surface such as polypropylene. Teflon is heated continuously in a thin layer, and those Teflon etc. are heated in an alternating current field. And its surface acts as a mold release agent. Heat treatment is w,’r, rose and Anchor Opt Trolley, like the model MBS-1 manufactured by New York). The process is carried out in a dielectric furnace until most of the hydroxyethyl methacrylate is polymerized. be called. The heating process takes, for example, 1.5 minutes, at which time the upper electrode is placed on the top of the beads. It is located 1/4 inch above the top. Next, add PMMA beads to about 70-80? of Cool to room temperature, crush the aggregates using a mortar and pestle, and then sieve continuously. Ru.

Since the resulting modified PFil1MA beads contain a residual amount of monomeric HEMA, Boil the beads in water for about 2-3 minutes to extract residual monomer. Then PM Spread the MA peas and allow to air dry or dry thoroughly without causing melting. Force dry at a temperature that is not too high.

Loose, non-bonded modified PMMA beads have a water-wettable PHEMA coating. Then, barium sulfate is embedded in it. All barium sulfate is PMMA bee Therefore, there is no residual free barium sulfate. barium sulfate The solvent must be present in an amount to substantially prevent binding between the PMMA particles. stomach.

Therefore, if the amount of PHEMA coating increases, the barium sulfate used A corresponding increase in the amount of time is required.

If PMMA beads are to be filled into a cavity within a hard tissue area, the beads may be slightly In addition, ties used to transport dental instruments such as silver amalgam 'PHE' was used to make it easier to handle in the form of agglomerates. It is advantageous to wet the MA coating with water to further swell it.

The bone surface that is in contact with the prosthesis is advantageously prepared in various ways. Tartar or Any residual layer on the surface of the bone, as well as any diseased bone in contact with the prosthesis, should be removed. Ru. This is accomplished, for example, by using a round dental parr. For oral application In this case, remove the tartar using either a root-carrying instrument or an ultrasonic tartar remover, or remove the root surface. Curettage of the diseased bone and tartar and residual layer on the root of the tooth in contact with the bone defect It is also desirable to remove . The cleaned root surface is then soaked in a mild acid solution, e.g. Treat with a 50% aqueous solution of citric acid or phosphoric acid for about 2 minutes, then wash with water. Ru.

Mild acid treatment helps in collagenization of the roots and thus promotes reattachment.

The foregoing detailed description is provided by way of example only and there are several variations to the invention. It is to be understood that this can be done without departing from.

Claims (1)

[Claims] 1. A filling material for forming a prosthetic implant for hard tissue in vivo, the filling material comprising: Contains no separate particles, each particle comprising a biologically compatible polymeric material. and an outer coating that entirely surrounds the inner core; The outer coating does not include a biologically compatible hydrophilic polymeric material, and each particle is a prosthetic implant made from a material with particles visible on the principal x-ray radiograph. A sufficient amount of barium sulfate is added to make the particles incapable of tissue growth. Prosthetic implants for hard tissue are formed in the gaps between compressed particles of the prosthetic implant that form pores. filling into human body cavities that have at least one surface comprising hard tissue to The filler material is of a size that should become the material of the separated particles so as to be separated. 2. The diameter of the particles is within the range of about 590 to about 840 microns. Filling material according to item 1. 3. Claim 2, wherein the core of the particle is composed of an acrylic polymer material. Filling materials listed in section. 4. Claim 3, wherein the core of the particle is a polymethyl methacrylate bead. Filling materials listed in section. 5. Claim 4, wherein the polymethyl methacrylate beads contain a plasticizer. Filling material as described. 6. Is the core of the particle a colimer and comonomer of methyl methacrylate? The filling material according to claim 3, comprising: 7. The claimed hydrophilic polymer material is polymeric hydroxyethyl methacrylate. Filling material according to scope 3. 8. The weight of the polymer hydroxyethyl methacrylate relative to the weight of the core of the particles The fill according to claim 7, wherein the quantity proportion is within the range of about 0.04 to about 0.07. material. 9. The polymeric hydroxyethyl methacrylate is monomeric hydroxyethyl Claim 8 comprising a copolymer of methacrylate and a crosslinker. filling material. 10. Claims wherein the crosslinking agent is triethylene glycol dimethacrylate. Filling material according to item 9. 11. Triethylene relative to the weight of the monomer hydroxyethyl methacrylate The weight percentage of glycol dimethacrylate is in the range of about 0.01 to about 0.05. , the filling material according to claim 10. 12. The method of claim 1, wherein the barium sulfate is located within a coating of hydrophilic polymeric material. Filling material according to range 7. 13. The weight ratio of barium sulfate to the weight of the core of the particles is about 0.25 to about 0. 13. The filler material of claim 12 within the range of 43. 14. the barium sulfate is in the form of particles having a diameter of less than about 1 micron; The filling and material according to claim 13. 15 Next step: a) Polymethyl methacrylate and barium sulfate with a particle size of less than 1 micron. 10-20% by weight or 215-43% by weight: b) monomer hydro Approximately 4-7% by weight of xyethyl methacrylate (of polymethyl methacrylate beads) ) was added to the polymethyl methacrylate-barium sulfate mixture, then PMMA Mixing the mixture for uniform coating of beads: C) Applying the mixture obtained in step b) above in a silicone rubber mold or on a non-polar surface. Hydroxyethyl methacrylate from 1/16 inch thick until polymerized. heating process; d) cooling the mixture to a room temperature of about 70 to about 80'F; e) breaking up the agglomerates in the mixture; f) boiling the mixed food in water for about 2-3 minutes; Retireable process: Next g) Spread the resulting modified polymethyl methacrylate for natural or forced drying. the separated individual modified polymethyl methacrylate peas, A method of manufacturing a porous implantable prosthesis comprising an assemblage of.