Development and application progress of biomedical titanium and alloy materials

1.Overview
Biomedical materials is an important branch of material science.It is a new carrier material with high technical content and high economic value,which is used to diagnose,treat or replace human tissues and organs or enhance their functions.It is a new developing field in material science and technology.Biomedical materials make greater contributions to exploring the mysteries of human life and ensuring human health and longevity.
For more than 10 years,the market growth rate of biomedical materials and products has been maintained at about 20%-25%.It is expected that in the next 10-15 years,the medical device industry,including biomedical materials,will reach the market scale of pharmaceutical products and become the pillar industry of the world economy in the 21st century.
Among biomedical metal materials,titanium and its alloys have become the preferred materials for medical implant products such as artificial joints(hips,knees,shoulders,ankles,elbows,wrists,finger joints,etc.),bone trauma products(intramedullary nails,plates,screws,etc.),spinal orthopedic internal fixation systems,dental implants,dentures,dental orthopedic wires,artificial heart valves,interventional cardiovascular stents,etc.At present,there is no better metal material than titanium alloy for clinical use.Developed countries and world-renowned implant product suppliers attach great importance to the research and development of titanium alloy,and have launched a series of new medical titanium alloy materials,including bioactive titanium alloy bionic materials.They have also made many patented designs and developments in the surface treatment of medical titanium alloy materials,giving medical titanium alloy materials better bioactivity to meet the physiological needs of the human body,So as to achieve the purpose of early rehabilitation of patients.
The world population is nearly 6.5 billion.According to incomplete statistics,there are nearly 400million disabled people,60million physically disabled people,and 2billion dental patients.At present,there are only 35million people implanted with biomaterial devices,and the annual amount of joint replacement is about 1.5 million,which is far from the number of people who actually need replacement.Therefore,the market demand potential of biomedical materials is huge.As the first choice of Biomedical Metal materials,the demand for titanium and its alloys will also increase greatly,so it is imperative to strengthen the research and development of medical titanium alloy materials[1].
2.Development history,latest progress and market situation of biomedical titanium and its alloys
The development and application of biomedical titanium and its alloys have experienced four landmark stages.
2.1 initial application
In the early 1950s,first in Britain and the United States,commercial pure titanium was used to make bone plates,screws,intramedullary nails and hip joints.Because the bone plate needs to be shaped during surgery in order to apply the physiological and anatomical shape of the broken bone,until now,commercial pure titanium(is05832-2)after special processing is still used to manufacture bone plates and supporting screws,such as the full series of AO plates and screws produced by the designated manufacturer of Ao bone fixation implants,Mathys Medical Ltd.,Switzerland,which cannot be replaced by high-strength titanium alloy.It is clinically found that there are obvious problems of insufficient strength and stiffness in the manufacture of intramedullary nails and hip joints using commercial pure titanium.In order to avoid fracture failure of internal fixation implants and improve the strength of implants,high-strength Ti-6A1-4V(is05832-2)alloy has been used to replace pure titanium materials in Britain,the United States,Russia,Japan and other countries.
2.2 development stage
Ti-6A1-4V alloy itself is also developing.Ti-6a1-4veli high damage tolerance titanium alloy with high fracture toughness,low crack growth rate and low interstitial elements has emerged.Up to now,this alloy still accounts for more than 80%of titanium alloy implant products.
Although Ti-6A1-4V alloy has excellent properties,because V element can cause malignant tissue reaction and may have toxic and side effects on human body,it has prompted materialmans to study new titanium alloy materials without v.Since the 1980s,biomaterialists in Germany and Switzerland have successively developed ti-5a1-2.5fe and ti-6a1-7nb alloys.Among these two alloys,the clinical application of ti-6a1-7nb(is05832?11)alloy is more successful.In 1985,ruisulzer medical technology company first used forged ti-6a1-7nb-protasu1100 material to manufacture hip joint handle,and obtained the quasi production registration[2],which is used in clinic,and the market reflects well.At present,this kind of product has been introduced into China.Mathys of Switzerland also uses ti-6ai-7nb alloy to manufacture non reamed interlocking intramedullary nail system(including tibia,humerus and femur)and hollow screws for the treatment of femoral neck fractures.
2.3 improvement stage
Since the 1990s,in terms of titanium alloy implant materials,there have been reports about the potential harm of aⅡto human body,and it is believed that A1 will cause osteoporosis and mental disorders.Therefore,biomaterialists began to explore and study new biological titanium alloys without V and A1.Among them,ti-13nb-13zr alloy(ASTM f1713-1996)and Ti alloy have been successfully developed and have been clinically approved.12mo-6zr-2fe alloy(ASTM f1813-1997).
Ti-13nb-13zr alloy is a bio titanium alloy with good comprehensive properties such as low elastic modulus,high strength,high toughness,high fatigue strength and good biocompatibility,which was developed by American scientists in the early 1990s.Compared with Ti-6A1-4V,its elastic modulus is 30%lower and its plane fracture toughness is 20%(65mpa.M1/2);The bending and shear modulus are 30%-40%lower,and the corrosion rate in the same human simulated body fluid is 40%.After cold and hot processing,while maintaining high strength,the modulus can be reduced to 50MPa,which is closer to human cortical bone[3].At present,this material is used to make dental implants by internationally renowned dental material manufacturers.
Ti-12mo-6zr-2fe alloy is also a biomedical titanium alloy respected by international well-known metal implant manufacturers in recent years.This alloy has low elastic modulus,high strength,high fracture toughness(90mpa.m1/2),good wear resistance and excellent corrosion resistance.It is a metastable p-type biomedical titanium alloy with good comprehensive properties.Compared with Ti-6A1-4V,its elastic modulus is 25%lower,the softness of the material is better,the fracture toughness is about 80%(90:52),and it also has excellent mechanical properties:the tensile strength is 20%higher than Ti-6A1-4V,and the fatigue strength is 47%.One of the largest orthopedic professional group companies in the world??Stryker howmedia osteonics(Stryker joint branch),a subsidiary of Stryker group,uses ti-12mo-6zr-2fe alloy(tmzfr beta)to manufacture meridiantmzf femoral stems in howmedia partnership system(hip prosthesis system).This system has reached the highest standard of orthopedic clinical requirements in terms of quality,function and clinical effect??Top level.Stryker spine(Stryker spine branch)also uses timozrfe alloy to manufacture the anterior cervical plate system(reflex anterior cervical hate).The above two products have been introduced into the Chinese market.
2.4 innovation stage
No innovation,no progress.In recent years,there are many innovative achievements in medical titanium alloys.
(1)Development and application of Ni Ti shape memory alloy(ntsma)
In the early 1980s,Ni Ti shape memory alloy successfully dried orthopedic clinic,which attracted the attention of orthopedic experts and clinicians,and was called"magic metal".This functional material has peculiar shape memory effect,super elasticity,fatigue resistance,wear resistance,corrosion resistance and good biocompatibility.It is composed of 56%by mass of Ni and 44%by mass of titanium.The deformation temperature of ntsma used in orthopedic clinic is 0℃-5℃,and the recovery temperature is about 37℃.After fixing the fracture with ntsma material,the shape recovery is produced by heating up under the body temperature or hot saline wet compress,but the bone restricts the material recovery,so that a dynamic and continuous pressure or clamp force is generated at the fracture end to fix the fracture.The basic research of ntsma materials in China is later than that in foreign countries,but it is in the international leading position in clinical application research.In 2000,in terms of orthopaedic implants,Lanzhou Ximai Memory Alloy Co.,Ltd.obtained the product approval registration from the State Drug Administration,which promoted the clinical application of ntsma orthopaedic implants.At present,three enterprises in China have registered to produce ntsma internal fixation devices,mainly including staples,patellar concentrators,encircling steel plates,Ni Ti arch memory compression connectors,intramedullary nails and other products[4].
Ntsma is also used in interventional therapy.Interventional therapy is an advanced non-surgical clinical technology that has developed rapidly in recent 10 years.This technology usually uses the puncture and intubation technology under the monitoring of X-ray images to deliver the specially made wires,catheters,balloons or support brackets along the blood vessels or other lumens in the body to the pathological changes in the body for on-site treatment.It has the characteristics of light trauma,little pain,low risk,time-saving,reliable and fast recovery.Interventional therapy materials include stent materials and delivery system materials,among which ntsmao is the first choice.Interventional therapy in China has developed rapidly in recent years,with an annual growth rate of 20%-30%.In 2002,nearly 150000 patients received interventional therapy.At present,the materials required for interventional therapy are mainly imported,and more than 20 enterprises have obtained FDA certification to enter the Chinese market.Its product quality and performance are better than domestic products,and the after-sales service is in place,but the price is expensive,about 12000 yuan/piece-16000 yuan/piece.The main suppliers are johnson&johnson company cordis Co.,medro nig,Inc,and Canada's numed Canada Inc;There are also some companies in China,such as Beijing Sitai new technology development company,Beijing Xinquan company,Beijing Longzhou Feidu Memory Alloy Application Research Institute,etc.
In addition,ntsma is also used in dental orthodontics.Ntsma dental arch wires produced by Xigui Institute of Beijing Nonferrous Metals Research Institute(now Beijing Youyan Yijin Co.,Ltd.)are not only sold and applied in China,but also exported overseas.
(2)Fabrication of cervical and lumbar interbody fusion cage(cage)with porous Ni Ti(pnt)alloy bioactive materials
Biorthex company of Canada has developed a cervical and lumbar interbody fusion cage made of porous Ni Ti alloy patented material actiporetm for the treatment of orthopedic spine injury.This material has a porosity of about 65%and an average pore size of 215μm-230μm.With biological activity,it can promote the rapid growth of new bone through micropores and scaffolds.The micropores connected with each other in multiple directions inside produce capillary penetration,and promote the blood,basic nutrients and bone marrow to enter the interbody fusion cage.The elastic modulus of this metal implant material is close to that of cancellous bone,thus avoiding the stress shielding effect,promoting bone reconstruction and providing good environmental support for the growth of bone cells.Bone growth cells and nutrients penetrate into the interconnected micropores to accelerate bone integration.The biggest feature of this interbody fusion cage is that it does not need bone grafting(other interbody fusion cages need bone transplantation,using their own iliac bone).3.1 years after transplantation,bone reconstruction is completed in the cage and matched with the surrounding bone density.Through animal experiments,pnt alloy has good biocompatibility[5,6].In 2000,the product obtained CE certification and began to be sold in European and some Asian markets.At present,more rigorous clinical validation is being stepped up to apply for FDA certification.The product is also expected to be introduced into the Chinese market in the near future.
(3)Artificial hip prosthesis made of porous titanium alloy
Biological fixed(non cemented)artificial joint is a kind of artificial joint prosthesis highly recommended by experts and clinicians in the field of orthopaedics.It requires that the material or surface of the hip joint handle has biological activity,which can induce the growth of bone cells,and make the interface between the joint handle and the femoral medullary cavity produce bone integration,so as to avoid the disadvantages of bone cement fixation,that is,loosening,sinking and dislocation after long-term use.Therefore,the use of porous titanium alloy in some stages of the joint handle will endow the prosthesis with biological activity and contribute to the bony physiological combination of the handle and the medullary cavity.In the late 1990s,scientists in Germany and Japan successfully used directional solidification technology to prepare directionally solidified porous metal materials(i.e.foam metal)with hydrogen,oxygen and nitrogen as foaming gases.Krupp(GB implantat technologie GmbH)of Germany used this technology to produce porous titanium alloy femoral stem prostheses.
(4)Porous titanium alloy coating technology for artificial joint prosthesis manufacturing
Another method of manufacturing biological fixed artificial joints is to produce pores on the surface of titanium alloy joint handles.Tiny titanium beads(microsphere powder)can be sintered or plasma sprayed,and the particles can be sintered(generally double-layer or three-layer)or plasma sprayed on part of the surface of the joint handle,making its surface porous,reducing the difference between the elastic modulus of the implant and bone,which is conducive to the growth of bone cells and the delivery of nutrients,so as to obtain physiological bone integration.For example,titanium beads with a diameter of 0.28mm are used at the proximal end of the hip joint handle of exactech acumatchtm-a Series in the United States,which are arranged in three dimensions.After sintering,the sum of the three rows of beads is 0.84mm,and the average pore size is 152μm.The average void ratio is 35%,which indicates that 35%of the bone grows into the space on the surface of the sintered titanium beads in the handle.
Biological fixed joint prostheses(hip and knee joints)are mostly coated with porous spray(titanium microsphere powder),such as Zimmer company,exactech company,Taiwan United Company,etc.In addition to plasma spraying of titanium alloy beads(microspheres),Encore Medical Corporation of the United States has invented 3dmatrix porous spraying technology in recent years.Instead of using spherical particles,this technology uses a random three-dimensional shaped particle with a particle size of 180μm-850μm.Surface aperture size after spraying 250μm-450μm.The porosity can reach 61%.Clinical research shows that:100μm-500μM pore size is most suitable for bone growth.This advanced porous spraying technology makes the surface of the prosthesis stem have better bioactivity and provides a better bone growth interface.
(5)Hydroxyapatite(HA)coating technology used in the manufacture of titanium alloy artificial joints
Using plasma spraying technology to spray a part of the joint prosthesis stem with hydroxyapatite(HA)coating is also one of the methods to manufacture biological artificial joints.Structurally speaking,human bone itself is a natural composite material composed of osteogenic fibers and hydroxyapatite.Hydroxyapatite(Ca5(0h)(P04)3)contains hydroxyl groups that can bond with human tissue.Its chemical composition and crystal structure are very similar to that of hydroxyapatite crystals that constitute human tissue.After implantation into human hard tissue,it can bond well with bone,and can induce bone tissue to grow into micropores,with slight tissue reaction.After several months of implantation,bone bonding can generally be achieved at the closely matched interface,which has become the preferred coating material in bioactive ceramics.
The bonding strength between HA coating and titanium alloy matrix is the key to affect the clinical application effect of titanium alloy implants.As long as there is a macro interface between the coating and matrix,the bonding strength between them is not satisfactory.Generally,the bonding strength between the coating and titanium alloy matrix shall not be less than 40MPa,and the coating thickness shall be 150μm-200μm。The coating is too thick,the bonding strength decreases,and the coating is easy to crack.Therefore,the whole plasma spraying process is operated by robots to ensure the uniformity and consistency of the coating thickness.The coating contains micropores and larger pores,which are porous and random.The pore size of micropores is 3μm-5μm.The aperture size of the larger hole is 50μm-100μm。The pore size can be detected by scanning electron microscope.At the same time,ha must maintain continuous purity(generally more than 99.9%)and stable crystal structure.
Most joint manufacturers at home and abroad have used this technology to manufacture biological titanium alloy prosthesis stems.
(6)Al2O3 ceramic coating technology for titanium alloy artificial joint manufacturing
Using plasma spraying technology,the purity of 99.8%α?Al2O3 micro powder is sprayed on the hip prosthesis stem(stem material Ti6A14V),and then cooled in liquid C02 to form at its interfaceγ-Al2O3,at the same time,requires that the crystallization strength between the matrix and A1203 should not be less than 20MPa,which is also one of the methods to manufacture biological(non bone cement)artificial joints.Al2O3 ceramic materials are also used to make hip ball joints and hip socket liners.The autopsy of the deceased who used the prosthesis made of the above materials and other clinical tests showed that the debris of A1203 ceramic material did not cause the inflammatory reaction of synovial tissue in the joint capsule,and synovial hyperplasia and necrosis were not seen.This prosthesis is most suitable for patients with younger age and greater postoperative activity.It can be seen that Al2O3 ceramic material has excellent biocompatibility with human tissue.Al2O3 ceramic materials also have high physical stability,no biological degradation,excellent hydrophilicity on the surface of the material,and can effectively form a water molecular film to reduce friction,hardness and fatigue.High labor strength and wear resistance are 30-40 times higher than that of CoCrMo alloy.The joint products of Italian Lima orthopedic equipment company and French serf medical technology company adopt this manufacturing method and process.This process is also used in the joint products of Baimu aviation materials company of Beijing Institute of aeronautical materials.
(7)Hydroxyapatite(HA)-glass titanium composites for artificial joints
In the late 1990s,Japanese materials scientist Takeshi maruno and others developed a new biomedical titanium alloy composite for artificial joints.This material is based on Ti-6A1-4V alloy.Glass powder(alumina borosilicate glass,i.e.al2o3-b2o5-sio2,volume percentage is about 85%,and the rest are glass modified oxides Na2O,K2O,Li2O,ZrO2 and TiO2)with good adhesion to the matrix material,stable biochemical properties and safety properties,basically no reaction with HA,and excellent adhesion with HA powder is selected.The average diameter of glass powder is 17μm)High purity HA powder was mixed with it and coated on the surface of titanium alloy matrix to form glass titanium composites containing ha.Another key to the study of this material is that the thermal expansion coefficient of the sintered composite layer is lower than that of the titanium alloy matrix.Only in this way,the contact interface between the composite layer and the titanium alloy matrix can produce a dense,stable composite layer that is closely combined with the matrix material due to thermal diffusion reaction.
The artificial hip prosthesis stem made of HA-G-Ti composite material has been proved to be a cheap artificial hip prosthesis with strong durability and excellent initial fixation through preliminary clinical verification.The HA-G thickness of the composite layer can be adjusted arbitrarily,with excellent biocompatibility.The HA-G composite layer has good adhesion to the matrix,and peeling and spalling have not been found.The long-term clinical effect needs to be further observed,so this material is also a biomedical titanium alloy material with great market development potential[7].
(8)The surface of titanium and its alloys is anodized and colored for orthopedic equipment,plastic surgery and dentistry.
Anodizing and coloring the surface of titanium and its alloy,in terms of its functionality,coating oxide film on the surface improves the wear resistance,corrosion resistance and cyclic fatigue resistance of titanium alloy matrix in human environment.In addition,the oxide film on the surface also solves the problem of metal ion dissolution to a great extent,reduces cytotoxicity,and greatly improves the biocompatibility of the implant.For its aesthetics,with the gradual increase of the types and specifications of titanium implants,it also brings trouble to clinical recognition.As a unique attribute of titanium alloy,the hair color of surface oxide film can be used to identify implants of different specifications and categories in surgery,which is convenient for surgical operation.In addition,due to its good biocompatibility,corrosion resistance,light weight and comfortable wearing,titanium as denture(implant)and orthopedic restoration is gradually increasing in clinical application.People's restoration of dentures has not only emphasized the restoration of chewing,pronunciation,service life and other functions,but also increased the requirements for the beauty of dentures.The color beauty of dentures can give people visual aesthetic enjoyment[8].In plastic surgery repair,this advantage is even more obvious.
The reason why the titanium surface shows different colors after oxidation is that the main component of the oxide film formed on the metal titanium surface is titanium oxide.The thin film material composed of this component is transparent and can strongly reflect and refract light.When titanium is heated in an oxygen atmosphere or anodized,a layer of titanium oxide film with a thickness of several hundred a is coated on the surface of titanium.If light shines on titanium coated with oxide film,the reflected light on the oxide film surface will interfere with the light reflected on the metal interface through the transparent oxide film,showing various beautiful interference colors[9].With the different thickness of oxide film,titanium surface can show yellow,green,gold,pink and other different colors.
The oxidation coloring of titanium mainly includes anodic oxidation,atmospheric oxidation and chemical treatment.In addition,there are plasma nitriding,nitrogen ion implantation,physical chemical vapor deposition and other methods.
Compared with the other two oxidation coloring methods of titanium,the anodic oxidation method has simple process,rich color tones of surface coloring,and the color tones are easy to control,so this oxidation method is the most promising oxidation coloring technology.
The surface coloring treatment of bone fixation implants and instruments usually adopts anodic oxidation method,and its colors include:golden yellow,bronze,sapphire blue,bright brown,rose red,elegant green,etc.
3.Research,development,sale,market application and preliminary analysis of existing problems of biomedical titanium and its alloys in China
3.1 current situation of research,development and market application of biomedical titanium and its alloys
Since the mid-1980s,the clinical and Application Research of NiTi shape memory alloy in medical implants in China has reached the international advanced level.Shanghai Iron and Steel Research Institute,Tianjin Metallurgical Materials Research Institute and Rare Metals Research Institute of Beijing Nonferrous Metals Research Institute have jointly developed many medical implant products with local medical experts and professors.Such as:embracing steel plate,patella claw,cross stitch nail,intramedullary nail,artificial joint,dental arch wire and other products.However,it was not until 2000 that the first nickel titanium shape memory alloy product(from Lanzhou Ximai Shape Memory Alloy Co.,Ltd.)was approved and registered by the State Pharmaceutical Administration.
Although China is rich in titanium reserves,it lags behind in medical titanium,which cannot be compared with Europe and the United States in terms of scientific research,equipment,technology,process,or application.In 1998,the second orthopedic device factory of Tianjin medical device industry company was the first to obtain the trial production registration of"titanium bone plate"and"titanium bone screw"issued by the state medical administration,and became the first titanium implant manufacturer in China.The enterprise achieved good economic benefits that year.In the next few years,titanium implants have mushroomed by domestic medical device manufacturers.At present,enterprises with better application in China include Changzhou Wujin No.3 medical device factory,Changzhou Kanghui medical device Co.,Ltd.,etc.However,many problems have also occurred in the specific use process,such as fatigue and fracture of implants,difficulties in shaping during surgery,and even many medical disputes,which of course has a lot to do with the choice of materials.
In 1992,China formulated the standard of titanium and its alloy processing materials for surgical implants(gbl3810-1992),but there are few kinds of alloys.In 1997,the above standard was revised,namely gb/t13810?1997。However,in actual use,the manufacturers of surgical implants have not fully understood the performance of this material,and the material manufacturers have no internal control standards for surgical implant materials.For example,the ti-6al-4veli high damage tolerance alloy standard commonly used by foreign surgical implant manufacturers has not been popularized and applied in China at present.
In the research and development of biomedical titanium and its alloys,Professor wangguisheng of Beijing Nonferrous Metals Research Institute,Professor weishouyong of Baoji Nonferrous metals processing plant,and Professor Li zuochen of biomaterials research center of Northwest Nonferrous Metals Research Institute have done a lot of useful work and exploration.
In terms of the development of Ti-6Al-7Nb alloy,since 1996,it has been approved by the state medical administration,and has successively completed laboratory research and industrial trial production through the joint efforts of Beijing Nonferrous Metal Research Institute,Baoji Nonferrous Metal processing plant and their cooperative units.The chemical composition and mechanical properties of the material fully comply with is05832?11.It is stipulated that the metallographic structure is equivalent to grade A4 in the European titanium products Technical Committee(etyc2)standard,and conforms to iso5832?11 requirements for microstructure.In addition to the small batch trial investment of this material,Baoji Nonferrous Metal processing plant also exported more than ten tons of finished bars to the United States in 1999,earning hundreds of thousands of dollars in foreign exchange[10].This material passed the expert appraisal in 2001,and this project also won the first prize of China Nonferrous Metals Industry Science and Technology Award in 2001.
At present,the material has been prepared to be incorporated into the revised version of the national standard general technical conditions for bone grafting and non active surgical implants(gbl2417).The national standard of Ti-6Al-7Nb bar for surgical implants is also under preparation.
3.2 existing problems
At present,although many implant manufacturers have taken titanium alloy implants as the focus of product development,and the number of titanium for medical use is rising sharply(relative to themselves),there are still many misunderstandings in China's titanium for medical use:implant manufacturers lack unified and high-quality internal control material standards,lack scientific understanding of material brand and performance,and blindly believe that all titanium is good,As a result,many implants were broken and failed in vivo due to product materials,resulting in medical disputes:
Due to the amount of use,the material manufacturer considers the cost factor,only emphasizes the economic benefits,ignoring the social benefits.Domestic material manufacturers have not yet produced titanium products for medical use,such as ti-6a1-4veli alloy commonly used by European and American companies,including profiles,such as arc-shaped cross-section panels,small-diameter hollow thick wall pipes,joint forged thick plates,etc;
Due to various reasons,the research and development of titanium alloy materials for medical use in China is insufficient.Compared with advanced countries in the world,the processing and surface treatment of titanium alloy implanted products are far behind;
Although the State Council has set up the national titanium industry management office,due to the particularity of medical materials,China has not established a special branch or industry association that is responsible for or coordinates the research and development,material standards,material quality control,product processing technology consulting and exchange of medical titanium,and there is a lack of unified industry management.
4.Outlook
(1)Attention should be paid to the development of biomedical titanium alloy materials with low elastic modulus,high wear resistance,corrosion resistance,high fracture toughness,low crack growth rate,high damage tolerance,and excellent biocompatibility;
(2)The compatible elements constituting the alloy should be based on the premise of paying attention to the addition of non-toxic elements,such as mainly adding non-toxic"biological"metal elements,such as Nb,Zr,Ta,Sn,Pt,etc;
(3)Efforts should be made to improve the quality level of biomedical titanium and its alloy processing materials in China.Manufacturers should pay attention to and meet the market demand for medical titanium,the quality control standards of materials should be in line with international standards,and strengthen the standardization of materials;
(4)We should strengthen the development and research of materials,take the joint development path of material research institutes or colleges,material manufacturers and medical research institutions,and clinical medical experts,integrate material development,biocompatibility test,and clinical medical verification,and accelerate the development of new biomedical titanium alloy materials with broad application prospects.

Author:hebaoming