Titanium is increasingly used in medical applications
At present, titanium and titanium alloy have been widely used in artificial bone joint, artificial bone, joint foot plate, bone fixator, bone marrow nail, artificial heart valve, skull and so on.
Application of titanium in transplantation
Artificial joint and artificial bone replacement materials should have the following basic properties: light weight and high strength materials, with biological compatibility, corrosion resistance, the tissue reaction of the implant in the body does not cause the deterioration of materials, repeated stress caused by fatigue, less damage and other properties. The most important properties of metal implants are formability, machinability, and polishing properties, which must be maintained over the expected life of the implant and not degraded during fatigue, wear, corrosion, and impact loading. Titanium and titanium alloys meet all of the above requirements. The earliest used denture powder, polypropylene, plexiglass and other artificial joint materials have low strength, easy folding and poor biocompatibility. Later use stainless steel, but the proportion of stainless steel is larger, about 2 times the proportion of human skeleton, and in the body by the body fluids will appear corrosion and fracture. Co-Cr alloy is also an excellent artificial joint material, but unfortunately, cobalt, chromium elements are toxic to the human body. Titanium and titanium alloy is an ideal artificial joint material with small specific gravity (similar to that of human bone), high strength, good mechanical processing and excellent corrosion resistance.
The titanium materials for surgical transplantation are mainly pure titanium and Ti-6AL-4V ELI alloy. Recently, the transplanting materials with good affinity to human body Ti-6Al-7Nb and Ti-13Nb1-13Zr have also obtained ASTM standard recognition. Using titanium as artificial bone, cells can regenerate on it, bone can grow, and titanium has good affinity with human bone, epithelium and tissue. In order to improve the surface quality of implantable materials connected with human bone, bioceramics layer on roughened surface is also an effective method.
Application of titanium in orthopaedic surgery
The elastic modulus of medical titanium alloy is closer to human bone than stainless steel, which is suitable for human orthopaedic surgery. In orthopaedic surgery, nickel-titanium shape memory alloys are commonly used. For the application of titanium alloy materials to the human body, countries are still continuing to explore, to seek a more secure and reliable new titanium alloy, for the benefit of people around the world.
Titanium is used in pharmaceutical industry
Titanium is mainly used to make containers, reactors and heaters in the pharmaceutical industry. In pharmaceutical production, the equipment is often exposed to hydrochloric acid, nitric acid, sulfuric acid and other inorganic acids, organic acids and their salts. The equipment is often damaged by corrosion, and the product quality is affected by iron ion pollution caused by steel equipment. The titanium equipment can solve these problems. For example, penicillin esterification kettle, saccharation tank, chloramphenicol film evaporator, analgin reactor, mituer filter, dimethyl sulfate cooler, liquid medicine filter, etc., all have the precedent of selecting titanium material. The quantity and quality of liquid medicine produced are constantly improved, and the quality is in full compliance with the regulations.
Application of titanium in medical apparatus and instruments
Titanium and titanium alloy have good corrosion resistance, titanium non-toxic, non-magnetic, is a good choice of medical equipment materials. In the history of the development of surgical instruments, the first generation of surgical instruments were made of carbon steel. The second generation of austenite, ferrite and martensitic stainless steel surgical instruments, but the stainless steel components of chromium toxicity, falling off the chromium plating layer on the human body has a certain impact, therefore, the emergence of the third generation - titanium surgical instruments. The lightweight nature of titanium makes it particularly suitable for microsurgery. Titanium has corrosion resistance, good elasticity, no deformation, resistant to repeated cleaning, disinfection surface quality is not affected; Non-magnetic, can eliminate the small, sensitive implantable electronic devices to destroy the threat of other characteristics, so that titanium surgical instruments more and more widely used. At present, it has been used to make surgical blades, hemostatic forceps, scissors, electric bone drill, tweezers and so on. Titanium vascular suture needle and sternum suture thread are used in medical instruments, titanium filter plate of oxygen filter is one of cardiac surgical instruments, titanium electrode is used in ecg machine, titanium incubator is used in in vitro culture machine; The probe of medical ultrasonic crusher, automatic controller of blood transport box and titanium instrument for eye surgery are all in good condition.
Dental applications of titanium and titanium alloys
Due to its excellent corrosion resistance and human affinity, and considering the metal sensitivity and specific strength, titanium is suitable for dental applications. The metal used in dental surgery, starting from amalgam and metal crown in the 1920s, was mainly used in gold, silver and palladium alloys in the 1960s. After the 1970s, stainless steel became the most commonly used material for permanent and removable orthodontic instruments. Titanium casting technology was popularized in the 1990s.Dental casting with titanium casting machine has the characteristics of high dimensional accuracy, no bubbles and shrinkage holes, etc. In the metal materials used for the repair of human hard tissue, the elastic modulus of titanium is the closest to human tissue, which can reduce the mechanical inadaptability between metal implant and bone tissue. Titanium has the lowest thermal conductivity among all metal materials used in dental restoration. Low thermal conductivity can reduce the thermal stimulation on the pulp of crown-tooth, which is very important for dental restoration. Titanium inlays, crowns and so on have the function of protecting dental pulp and avoiding cold and heat stimulation. In terms of the material, the original titanium used in dentistry is mostly pure titanium, but its strength is insufficient, it is difficult to grind, it has poor wear resistance, and it is easy to produce casting defects and quality instability.Ti-6Al-4V alloy is the most commonly used one due to its high strength. However, since metal V is harmful to human health, it can be replaced with Nb. Ti-6Al-Nb alloy has been successfully developed. At present, the superelastic Ti-Ni alloy is widely used in tooth straightening. Since the 1980 s developed countries began to study the application of titanium in oral cavity repair, first used in dental implants, and later used for denture stents, and tooth crown bridge is silk, the titanium for dental crowns, nail crown and fixed bridge, bridge PFM bridge, binding, denture card ring, underpinning, connection device and strengthen device, denture nearly all the metal parts can be made with titanium. The study of titanium and titanium alloys has become a hotspot in dental alloys. Titanium alloy porcelain teeth can be a very good restore tooth form and function, and high strength, good appearance, colour and lustre is stable, smooth surface, wear resistance, corrosion resistance, is a kind of permanent restoration, applies to all fixed tooth, especially its good biological compatibility, is suitable for people who are sensitive to nickel ions, has been widely applied in the restoration of teeth.