Method of applying hydroxyapatite coat on implants
FIELD: process engineering.
SUBSTANCE: invention relates to method of applying hydroxyapatite coats and may be used in medicine for production of met implants with bioactive coat. Proposed method comprises mixing hydroxyapatite powder with biologically compatible binder representing a phosphate binder with binder-to-powder ratio of 1.0-1.5:1.5-2.0, applying obtained suspension on metal surface, drying and thermal treatment by argon plasma jet at arc current of 300-500 A for 0.5-2.0 min at distance of 40-100 mm.
EFFECT: higher mechanical strength of hydroxyapatite coat.
2 dwg, 1 tbl, 2 ex
The invention relates to medicine, namely to methods for applying a bioactive hydroxiapatite coatings on implants for dentistry, traumatology and orthopedics.
Hydroxyapatite coating of implants provides fast and efficient engraftment in the bone structures due to the high level of biological activity of the surface. The most common technology of powder coating hydroxiapatite coating is plasma spraying [1-3], which consists in passing the powder of hydroxyapatite through the plasma torch, melting of the powder particles in the plasma jet and their subsequent deposition on the surface of the implant. However, the application of hydroxiapatite powder coating-plasma method is a technologically complex process and is characterized by low economic efficiency of the flow rate of the sprayed material, as only 40-50% of the particles hydroxiapatite powder is deposited on the surface of the workpiece, and the rest of their number - on the walls of the sputtering chamber, not getting on the product. In this case, the mechanical strength of the coating in many cases is low, there is often a rebound of the powder particles from the substrate in the collision with her.
A known method of manufacturing implants with bio-ceramic coating (hydroxyapatite Biosite), applied by plasma spraying . The disadvantage of this method is the high consumption of used powder material and inadequate for continuous functioning of the implant mechanical strength of the coating.
The closest prototype, according to the authors, is the method of applying hydroxiapatite coatings comprising mixing hydroxyapatite powder with a binder, which is used as the phosphate ligaments, taken in relation to the powder 1,0-1,5:1,5-2,0, drying and heat treatment annealing at a temperature varying between 250 and 600°C . The method is characterized highly economical consumption hydroxiapatite powder, because all of its particles, which is mounted on the implant surface using a binder, participate in the process of creation of the coverage. However, the disadvantage of this method is the lack of mechanical strength of the coating.
The objective of the invention is to provide a cost-effective method of applying hydroxiapatite coating with high mechanical strength.
This object is achieved in that a mixed powder of hydroxyapatite and biocompatible binder, which is used as the phosphate ligaments, taken in relation to the powder 1,0-1,5:1,5-2,0, put the resulting suspension on a surface is the surface of the implant, produce drying the applied suspension for preliminary fixation to the implant and carry out heat treatment of argon plasma jet at arc current 300-500 And duration of 0.5-2.0 min at a distance of 40-100 mm
The difference of the proposed method from the prototype is that the heat treatment is carried out by exposure to argon plasma jet at arc current 300-500 And duration of 0.5-2.0 min at a distance of 40-100 mm
Given the limits of technological processing mode provide hydroxiapatite coatings with high adhesion and cohesion, which are the main indicators of the mechanical strength of the coatings.
Effective heat of argon plasma jet when the value of the mode I<300 a, τ<0.5 min is impossible, since the resulting coating does not possess high mechanical strength and are prone to fracture even at low functional load on the implant. This is because heat treatment of argon plasma jet at such values of the mode does not provide surface melting particles hydroxiapatite powder, resulting in not is their increased interaction with the implant and with each other.
Argon-plasma treatment at values of I>500 a, τ>2,0 min creates the danger of burning particles of hydroxyapatite in the volume forms the alignment coating, what is technologically unacceptable factor.
Distance (distance from the nozzle of the plasma torch to the surface of the product) is selected depending on the dispersion applied hydroxiapatite powder and the thickness of the created bioactive coatings and varies from 40 to 100 mm for surface melting of the particles of hydroxyapatite and their strong relationship with the implant surface and to each other.
When the distance processing less than 40 mm, the strength of the relationship of the coating with the surface of the implant is increased, but no pronounced roughness and porosity hydroxiapatite layer required for osseointegration of the implant and its secure attachment to the bone. At a distance of processing in excess of 100 mm, excludes the possibility of melting particles hydroxiapatite powder with no conditions of their enhanced relationship with the implant and with each other, which leads to a considerable reduction of the mechanical strength of the coating.
The invention consists in that the process of forming the coating is carried out by mixing the powder of hydroxyapatite phosphate-bonded, applying the resulting slurry to the surface of the implant, drying the applied suspension for preliminary fixing of the amount of coating of the mandate Elie and heat treatment of argon plasma jet at arc current 300-500 And, duration of 0.5-2.0 min, at a distance of 40-100 mm, While the hydroxyapatite powder is mixed with a binder to hold hydroxiapatite particles on the implant surface, and heat treatment of argon plasma jet is performed to ensure that surface melting of the powder particles and their enhanced physical and mechanical interconnection with a metal base and with each other due to the effect welding of the particles. The presence in the volume of coating does not pereplavlennyj solid core particles of hydroxyapatite creates a pronounced roughness and morphological heterogeneity of the surface with the presence of porous structure necessary for effective osseointegration of the implant.
The coating obtained by the claimed method, illustrated with photos, in which figure 1 shows surface osteointegration structure hydroxiapatite layer formed on the titanium (VT1-00) the dental implant as in figure 2 - steel (HT) orthopedic implant-osteofixation.
Example 1. Prepare a suspension of the powder of hydroxyapatite dispersion Δ=50 μm and a biocompatible binder to the resulting solution was saturated with hydroxyapatite particles and contained the minimum amount of binder sufficient to hold the suspension of poweredtemplates. As binders take calcium phosphate ligament and mix it with the powder of hydroxyapatite in a ratio of 1.0:1.5 to. Using a brush, the resulting suspension is applied to the implant and is subjected to drying in an oven at 50°C for 20 minutes Then the implant with a fixed suspension is placed in a plasma chamber installation type VRESSE and produce heat treatment of the coating argon-plasma jet when the value of the arc current I=350 A, the duration τ=1,0 min at a distance of L=70 mm In data technological terms is the melt surface hydroxiapatite particles, their welding to the base of the implant and to each other while maintaining solid nuclei in the volume of the particles.
Example 2. Prepare a suspension of the powder of hydroxyapatite dispersion Δ=70 μm and a biocompatible binder to the resulting solution was saturated with hydroxyapatite particles and contained the minimum amount of binder sufficient to hold the suspension on the surface of the implant. As binders take manifestou ligament and mix it with the powder of hydroxyapatite in a ratio of 1.2:1,9. Using a brush, the suspension is applied to the implant and is subjected to drying in an oven at 50°C for 20 minutes Then the implant with a fixed suspension is placed in a plasma chamber to set the key and produce heat treatment of the coating argon-plasma jet when the arc current I=450 A, duration τ=1.5 min at a distance of L=90 mm, the result is a bioactive mechanically durable coating of the surface-melted particles hydroxiapatite powder.
Obtained by this method hydroxyapatite coatings have been tested for mechanical strength, determined by the methods of normal tear and shear. The results of the tests are presented in table.
The positive effect of increased mechanical strength of the coating shear and highly economical consumption hydroxiapatite of the powder is achieved by the fact that, due to surface melting of the particles during the heat treatment is strengthening their relationship with the implant surface and to each other, greatly increasing the strength of the coating, and the amount of powder of hydroxyapatite, which is applied to the surface of the implant in the form of a mixture with the binder, is involved in the process of creating a cover with the exception of the rebound of the particles and their shedding with a metal base.
Dental intraosseous implants of titanium VT1-0, VT1-00, as well as orthopedic transosseous osteofixation of titanium alloy VT6, VT and stainless steel HT, 12H18N10T, covered with the proposed method can achieve the best treatment results due to the increased mechanical strength b is aktivnogo coverage, continuing throughout the term of functioning of the products.
Sources of information
1. Buttowski KG and other Electroplasma plating in the production of intraosseous implants. Saratov: Sarat. state technology. University, 2006. 200 S.
2. RF patent for the invention №2146535. A method of manufacturing intraosseous dental implant plasmolen multilayer bioactive coating. Publ. 20.03.2000.
3. RF patent for the invention №2134082. The method of manufacture of implants for transosseous osteosynthesis. Publ. 10.08.1999.
4. RF patent for the invention №2157245. A method of manufacturing implants. Publ. 10.10.2000.
5. RF patent for the invention №2158189. The method of applying hydroxiapatite coatings. Publ. 27.10.2000 (prototype).
|The dispersion of powder of hydroxyapatite Δ, μm||Mode argon-plasma treatment||The strength of the coating to peel σ, MPa||The strength of the coating when the shift σ, MPa||The strength of the coating when the shift σ, MPa (prototype)|
|I, And||τ min||L, mm|
|50||350||1,0||70||21||the 3.8||2,07-of 3.07|
The method of applying hydroxiapatite coating on the implant, comprising mixing a powder of hydroxyapatite and biocompatible binder, which is used as a phosphate binder in a ratio of ligaments and powder 1,0-1,5:1,5-2,0, applying the resulting slurry to the surface of the implant, drying and subsequent heat treatment, wherein the heat treatment is conducted argon plasma jet at arc current 300-500 And duration of 0.5-2.0 min at a distance of processing 40-100 mm
SUBSTANCE: invention relates to a method of coating articles made from valve metals which are used as component parts of turbomolecular pumps. An article made from a valve metal selected from aluminium, magnesium, titanium, niobium and/or zirconium and alloys thereof, is coated with an oxide ceramic layer formed from metal using a plasma-chemical method. The ceramic layer has a barrier inter-phase layer adjoining the metal, whose surface is coated with a polymer formed from monomers in form of dimers or halogenated dimers of general formula I where R1 denotes one or more hydrogens or halogens; each R2 denotes hydrogen or halogen; and each R3 denotes a xylylene residue with formation of a dimeric structure. Said monomers are incorporated into a capillary system and then polymerised on the surface of the oxide ceramic layer in a vacuum.
EFFECT: invention enables to obtain coatings with uniform surface porosity and high resistance to aggressive and corrosive media.
10 cl, 1 ex
SUBSTANCE: sheet has insulating coating containing composite resin consisting of polysiloxane and polymer containing carbon element. Method involves application of composite resin and burning at temperature of 150 to 350°C till the coating with weight of 0.05 g/m2 to 10 g/m2 is formed.
EFFECT: obtaining the sheet with insulating coating providing high corrosion resistance and formability, which are equivalent to or higher than those properties of chrome-containing insulating coating.
16 cl, 6 tbl, 1 ex
SUBSTANCE: invention refers to sheet of electro-technical steel with insulating coating and can be used in engines and transformers. The sheet out of electro-technical steel containing poly-siloxane polymer is produced by applying coating liquid on surface of sheet and in successive baking. Coating liquid contains 100 weight shares of poly-siloxane polymer preliminary prepared with co-polymerisation of poly-siloxane with one or more organic resins and from 1 to 50 weight shares in sum of one or more coupling agents. Organic resins are chosen from a group consisting of acrylic resin, sterol resin, vinyl-acetate resin, poly-ether resin, urethane resin, poly-ethylene resin, poly-propylene resin, phenol resin, alkyd resin and epoxy resin. The coupling agent is chosen from a group consisting of melamine, isocyanate, silane agent of combination and oxazoline.
EFFECT: production of sheet of electro-technical steel possessing upgraded corrosion resistance and ability to perforating.
4 cl, 4 tbl, 1 ex
SUBSTANCE: inventions relates to continuous mode of metal surfaces, particularly it relates to titanium, titanium alloys and aluminium, implemented in the form of foil or cell structure. Method includes mechanical restoration of titanium or titanium alloy for removing of oxides from surface, preparation of sol-helium solution, plating of sol-helium solution with formation of coating on mechanically restored titanium or titanium alloy and application of epoxy adhesive coating on coated sol-helium solution. The second option includes cleaning of titanium, titanium alloy or aluminium, at least, one alkaline cleaner and aqueous degreasing agent, restoration of metallic material, at least, mechanical restorative, conditioning of metallic material by alkaline solution containing 5 - 50% of alkali, application of sol-helium solution on metallic material and plating of epoxy adhesive coating on sol-helium coating.
EFFECT: methods provides increasing of treated material ability to connection with other objects and to create epoxy-compatible adhesive layer on the metal surface.
13 cl, 2 dwg, 2 tbl
FIELD: formation of protective coatings for carbon containing components of electrolytic cell at aluminum production.
SUBSTANCE: method comprises steps of preparing liquid suspension of refractory material dispersed in solution of lignosulfonate binder; applying suspension as coating on surface of carbon containing component; drying coating.
EFFECT: improved resistance of carbon containing component against rupture at operation of electrolysis cell.
34 cl, 1 dwg, 4 tbl, 7 ex
SUBSTANCE: described method of modifying surface of implants from titanium and its alloys relates to electrochemical application of biocompatible hydroxyapatite-based coatings on implants from titanium and its alloys for use in traumatology, orthopedics and dentistry. Products are placed into water solution of alkali electrolyte, additionally containing hydroxyapatite within the range 0.1-1.5 wt %. Formation of coating is carried out in galvanostatic mode with current value ensuring obtaining of final value of anode voltage 370 V during 15 minutes. Duration of anode and cathode pulses - 150 mcs, repetition rate 100 Hz and pause between anode and cathode pulses 350 mcs. Ratio of average values of anode and cathode currents for a pulse 1a/1c c equals 1. Method allows to obtain 14±2 mcm thick coating with preliminarily specified microhardness within 150-300 MPa, for which purpose required concentration of hydroxyapatite in electrolyte is determined basing on the formula: T=312-117·C, where T is the value of microhardness HV0.1 [MPa], C - hydroxyapatite concentration [wt %] in water solution of 2% KOH.
EFFECT: method allows to regulate physico-mechanical, including strength characteristics of calcium-phosphate coatings.
3 cl, 3 ex, 1 dwg
SUBSTANCE: hereby is described calcium pyrophosphate-based ceramic biodegradable material manufacture method. Method includes powder of monetite synthesis in reaction of aqueous solutions of calcium nitrate and ammonium hydrophosphate, followed by moulding and burning. In accordance with invention of moulding, to powder of monetite 3-7 wt % of calcium chloride is added.
EFFECT: method allows obtaining of calcium pyrophosphate-based ceramic biodegradable material with grain size less than 5 mcm.
1 tbl, 1 ex, 2 dwg
SUBSTANCE: there is described method of obtaining of calcium phosphate nanoparticles, stabilised by salt matrix by interaction of components, first of which contains metal cation, and second contains anion. According to invention as the first component applied is water-soluble calcium salt, and as the second component, soluble orthophosphate, nanoparticles of water non-soluble calcium phosphate being formed, and salt matrix being formed from soluble by-product. Content of calcium phosphate nanoparticles in powder composite "oxide nanoparticles/salt matrix" constitutes 65-82 wt %.
EFFECT: method is aimed at creation of effective nanotechnologies, in order to prevent degradation, that is, aggregations of oxide nanoparticles of calcium phosphates.
5 tbl, 4 ex
SUBSTANCE: invention refers to the method for making bioactive calcium-phosphate coatings and can be used in manufacturing of orthopaedic and tooth prostheses. The method for making supported calcium-phosphate coating involves radio-frequency magnetron sputtering of hydroxyapatite target Ca10(PO4)6(OH)2 during 15-150 min with using argon as a working gas at pressure in a working chamber 0.1 Pa. The coating is settled over a support over a ring of magnetron cathode region, where field lines of magnetron magnetic field localise high-frequency plasma with maximal effect of charged particle on the support at specific power of high-frequency discharge 50 W cm-2 that provides formation of coating composition close to that of stoichiometric hydroxyapatite Ca10(PO4)6(OH)2.
EFFECT: application of the method ensures activation of coating crystallisation during growth with final phase formation that corresponds to composition of the target.
6 dwg, 3 ex
FIELD: medicinal materials, chemical technology.
SUBSTANCE: method for preparing calcium phosphate-base ceramic materials involves interaction of calcium soluble salts and soluble phosphates, separation of deposit, molding articles and their roasting at temperature 1000-1300°C. A deposit of the specific surface value 30-60 m2 is subjected for treatment at temperature 50-60°C with aqueous or alcoholic solution containing ions chosen from the following order: Na1+ 4, NO1- 3, Ca2+, Cl1-, Na1+, OH1-, HCO1- 3, K1+, Mg2+, Al3+, Zn2+, F1-, CH3COO1-, CO2- 3, SO2- 4, PO3- 4, HPO2- 4 and SiO4- 4 in the total concentration of ions in solution 1.6-4.6 M and in the volume ratio "solid phase/liquid" = (1-100):(1-25). Method involves stirring for 30-40 min, or a deposit is subjected for treatment with a solution containing ions taken from the following group: Ca2+, NH1+ 4, NO1- 3, Cl1-, HPO2- 4, Na1+, OH1-. Method provides controlling the material thickening process and ceramics microstructure that allows approaching its chemical composition and crystalline structure to natural bone. Invention can be used in medicine in making osseous implants.
EFFECT: improved preparing method, improved and valuable properties of materials.
2 tbl, 4 dwg, 2 ex
SUBSTANCE: there are described new materials and methods for preparing a titanium dioxide coatings for osteointegrated biomedical prostheses. The invention also refers to an endosseous implant containing biologically compatible metal materials; characterised by the fact that specified implant has a coating containing a nanocrystalline material, containing nanoparticles of formula (I) AOx-(L-Men+)j; (I) where AOx represents TiO2 or ZrO2; Men+ represents metal ion exhibiting antibacterial activity, with n=1 or 2; L represents a bifunctional organic molecule which can simultaneously contact metal oxide and with metal ion Men+; and i represents a number of L-Men+ groups fixed to one AOx nanoparticle.
EFFECT: coatings are formed by nanomaterials exhibiting antibacterial properties and provide osteointegration of implants and, at the same time, reduce rejection peculiar to inflammatory processes caused by infections which can develop next to implants.
19 cl, 1 dwg, 4 tbl
FIELD: medicine, pharmaceutics.
SUBSTANCE: invention refers to medicine, particularly to dentistry. There is offered a material which contains thrombocyte-enriched patient's autoplasma, titanium nickelide powder of particle size to 100 nm, 2.5% colloidal nano-structured silver of particle size to 20 nm. There is offered a method for making a material that implies that patient's blood is centrifuged, plasma is separated from the blood clot, the separated clot is homogenised, colloidal nano-structured silver, nickelide powder and prepared centrifuged plasma are added thereto, then the components are mixed by ultrasound to produced a nacre green homogeneous composition to be used within 1-2 hours.
EFFECT: invention provides reliable implant fixation in a bone, and restoration of the bone and connective tissue.
2 cl, 2 ex, 7 dwg
SUBSTANCE: invention refers to medical equipment and can be applied for making a biocompatible coating of medical intraosseous and transosseous implant of high engraftment level. The titanium and alloy coating contains titanium and copper oxides in a certain quantitative ratio, and lanthanum. The coating is formed on titanium and titanium alloys (BT 1-0, BT 1-00, BT-6, BT-16 etc.) by the electrochemical method sequentially in two electrolytes; at first, anodic oxidation is used to make a layer of mixed titanium and copper oxides in electrolyte of concentration 200 g/l of sulphuric acid with added 50 g/l of copper sulphate in distilled water with direct anode current; then cathodic incorporation enables generation of a lanthanum layer in the form of fragments in electrolyte of concentration 0.5 M of lanthanum salicylate in dimethyl formamide with direct cathode voltage 3 V.
EFFECT: method allows making the osteointegration oxide biocoating exhibiting bactericidal and anticoagulant properties.
2 cl, 1 ex
SUBSTANCE: invention concerns biology and medicine, and can be used for making plasters, bandages, prostheses and implants. A medical coating contains a monocrystalline carbon layer with chains of carbon and silver atoms.
EFFECT: medical coating is deposited on a base (a substrate) and has an entactic homeotropic structure.
8 cl, 6 dwg, 2 ex