RU2127568C1 - Implant for compensation of lower jaw defects - Google Patents

Abstract

FIELD: medical engineering; stomatology; maxillofacial surgery. SUBSTANCE: implant is made of biocompatible polymers containing medicinal substances. Implant has porous structure with fixed size of pores. Porous casing in the form of biodestructing polymeric thread wound in spiral is placed on biodestructing forming plate of variable section with end fastening areas. EFFECT: endurance of biomechanical loads within the entire period of inherent bond tissue regeneration. 2 cl, 3 dwg, 4 ex

Description

 The invention relates to the field of medical equipment, namely to implants used in dentistry, in maxillofacial surgery.

 It is known that osteoplasty uses porous implants of complex configuration made of ceramic with a fixed pore size, made, for example, of corundum ceramics. (Gudushauri O.N., Dumbadze G.G., Mikadze G.S. Results and prospects of using endoprostheses from corundum ceramics. 1985, N 11, pp. 124-128).

 This design of the porous material is related to its composition and cannot be made from biocompatible polymer compositions based on copolymers of alkyl acrylate or copolymers of lactide and glycolide, etc.

 Porous implants are known which are made by densely filling hydroxyapatite of a particular dispersed composition in a vicryl stocking. (Harle, F. and Kreusoh, Th .: Augmentation of the alveolar ridge with hydroxylapatite (HA) in a viral tube. Second Internat. Congr. Prerosth Surg., Palm Springs, 1987 (Abstr. 53)).

 This design does not provide rigid fixation of the external geometric parameters of the implant.

 As a prototype, a device was selected for restoring lost sections of tubular bones (a.s. USSR N 1768146 A 1, Bull. N 38, 10/15/92), including a central rod, a shell and a layer of porous material between the rod and the shell made of biocompatible polymers .

 The disadvantages of the design of this device are: the need for its assembly during the operation at the site of surgery; the absence of a fixed pore size of the porous material; lack of direct contact of the porous material with bone tissue at the site of implantation; lack of the ability to replace defects of complex configuration.

 The aim of the invention is to remedy these disadvantages, i.e. the creation of biocompatible polymers containing medicinal substances, implants to replace defects of the lower jaw with a porous structure with a fixed pore size.

 This goal is achieved by the fact that the implants are made of a biodegradable polymer forming plate of variable cross section with end fastening pads and a porous shell formed on the surface of the plate between the fastening pads in the form of at least two layers of helically wound with a pitch of 0.1 to 3 mm biodestructive polymer thread .

 Figure 1-3 shows the implants of various configurations.

 The implants contain a plate 1, made in such a way that the shell 2 wound on its surface corresponds to the shape and size of the replaced defect of the lower jaw, and the pitch of the turns allows the formation of a porous surface for germination of the newly formed bone tissue. The plate 1 has an end pad 3 with holes 4, allowing to fix the implant at the installation site. The plate is made of a continuous biocompatible composite material that can withstand biomechanical loads at the implantation site during the entire period of regeneration of own bone tissue. The shell is made of a biocompatible polymeric material - a fiber containing medicinal substances and allowing their prolonged local therapeutic effect.

 Example 1. The implant for the replacement of defects in the body of the lower jaw (figure 1) consists of a forming plate with a cross section between the mounting pads 2 x 6 mm and a distance between them of 30 mm, made of a copolymer of N-vinylpyrrolidone and methyl methacrylate reinforced with nylon fiber and a sheath made from 6 layers of spirally wound onto a plate with a pitch of 0.1 mm polymer thread containing 80 wt.% nylon fiber, 19.5 wt.% copolymer of N-vinyl pyrrolidone and butyl methacrylate and 0.5 wt.% potassium orotate.

 Example 2. The implant for the replacement of defects in the body of the lower jaw (figure 2) consists of a forming plate with a variable from 3 x 7 mm to 3 x 10 mm cross-section between the mounting pads and the distance between them 100 mm, made of a copolymer of N-vinylpyrrolidone and methyl methacrylate reinforced with polyvinyl acetate fiber and a sheath made of 2 layers spirally wound onto a plate with a 3 mm pitch of a polymer filament containing 20 wt.% oxymethyl cellulose fiber, 40 wt.% copolymer of N-vinylpyrrolidone and butyl methacrylate, 20 wt.% copolymer of N-vinylpi rrolidone and methyl methacrylate, 15 wt.% potassium orotate and 5 wt.% dioxidine.

 Example 3. The implant for replacing the defect of the chin of the lower jaw (Fig. 3) consists of a bent at an angle corresponding to the bend of the replaced fragment of the chin of the shaping plate with a section between the mounting pads 2.5 x 8 mm and a distance between them along the perimeter of the bend 80 mm made of a copolymer of N-vinylpyrrolidone and methyl methacrylate reinforced with nylon fiber and a sheath made of 4 layers spirally wound onto a plate with a pitch of 1.8 mm polymer thread containing 75 wt.% polyglycolide of fibers, 10 wt.% copolymer of N-vinylpyrrolidone and methyl methacrylate and 15 wt.% potassium orotate.

 Example 4. The implant for the replacement of defects in the body of the lower jaw (figure 1) consists of a forming plate with a cross section between the mounting pads 2 x 6 mm and a distance between them of 30 mm, made of a copolymer of N-vinylpyrrolidone and methyl methacrylate reinforced with nylon fiber and a sheath . Made from 5 layers of spirally wound onto the plate with a pitch of 0.5 mm polymer thread containing 55 wt.% Polydioxane fiber, 15 wt.% Copolymer of N-vinylpyrrolidone and butyl methacrylate and 30 wt.% Benemycin.

 Thus, the present invention allows to produce cruel structures of complex configuration with a fixed pore size from biocompatible polymer compositions, including drugs of various therapeutic effects.

Claims (2)

 1. The implant is made of polymeric materials for replacing defects of the lower jaw, including the central part and the shell, characterized in that the implant consists of a forming plate with a variable cross-section and end fixing pads made of a biodegradable polymer reinforced with a polymer fiber, and a porous shell formed on the surface of the plate between the mounting pads in the form of at least two layers of spirally wound with a pitch of 0.1 to 3 mm biodegradable polymer thread. 2. The implant according to claim 1, characterized in that the biodegradable thread is a composition of biodegradable polymer fibers, onto which a biodegradable polymer is applied, containing bactericidal and (or) stimulating bone tissue growth medicinal substances, in the following ratio of components, wt.%:
Biodegradable polymer fiber - 20 - 80
Biodegradable coating forming polymer - 10-60
Medicinal substances - 0.5 - 30

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