Titanium is becoming increasingly abundant in medical applications

Artificial joints and artificial bone replacement materials should have the following basic properties: lightweight and high-strength materials, biocompatibility, corrosion resistance, tissue reactions that occur in the implant body do not cause material degradation, and fatigue and damage caused by repeated stress are minimal. The core performance of metal implants includes formability, machinability, and polishability. They must maintain their functionality throughout their expected lifespan and not deteriorate under fatigue, wear, corrosion, and impact loads. Titanium and titanium alloys meet all of the above requirements. The early use of artificial joint materials such as dental tray powder, polypropylene, and organic glass had low strength, easy folding, and poor biocompatibility. Later, stainless steel was used, but its specific gravity is relatively high, about twice that of human bones, and it can corrode and fracture when exposed to receptor fluids in the body. Co Cr alloy is also an excellent artificial joint material, but unfortunately, both cobalt and chromium elements are toxic to the human body. Titanium and titanium alloys have a low specific gravity (similar to that of human bone), high strength, good mechanical processing, and excellent corrosion resistance, making them ideal materials for artificial joints.

The titanium materials used for surgical transplantation are mainly pure titanium and Ti-6Al-4VELI alloy. Recently, transplant materials Ti-6Al-7Nb and Ti-13Nb1-13Zr, which have good affinity with the human body, have also been recognized by ASTM standards. When titanium is used to create human bones, cells can regenerate on it, bones can grow, and titanium has good affinity with human bones, epithelium, and tissue. In order to improve the surface quality of implant materials connected to human bones, applying a bioceramic layer to the roughened surface is also an effective method. At present, titanium and titanium alloys have been widely used in artificial bone joints, artificial bones, joint footplates, bone fracture fixators, intramedullary nails, artificial heart valves, skulls, etc. According to statistics, China's annual demand for titanium alloy artificial joints exceeds 5000 sets, and the clinical application effect is good.

The application of titanium in orthopedic surgery

The elastic modulus of medical titanium alloy is closer to that of human bones than stainless steel, making it suitable for orthopedic surgery. In orthopedic surgery, titanium nickel shape memory alloys are commonly used. Research has shown that NT-SMA is a new material that integrates wear resistance, corrosion resistance, shape memory effect, pseudo elasticity, and acoustic damping. Its application in orthopedics is becoming increasingly widespread. In addition to commonly used bone plates, intramedullary nails, mandibular fixation, scoliosis correction, etc., Shanghai Changhai Hospital has also designed and clinically applied a series of NT-SMA devices, such as NT patellar concentrators, NT pedicle screws, NT arch shaped devices, and NT flycatcher devices (designed specifically for sacral reconstruction), which have achieved satisfactory therapeutic effects. For titanium alloy materials applied to the human body, countries are still constantly exploring and seeking safer and more reliable new titanium alloys to benefit people around the world.

Application of titanium materials in the pharmaceutical industry

Titanium is mainly used in the pharmaceutical industry to make containers, reactors, and heaters. In pharmaceutical production, equipment often comes into contact with inorganic acids, organic acids, and their salts such as hydrochloric acid, nitric acid, and sulfuric acid. Equipment is often damaged due to corrosion, and iron ion pollution caused by steel equipment affects product quality. The use of titanium equipment can solve these problems. For example, there are precedents for selecting titanium materials in penicillin esterification kettle, saccharification tank, chloramphenicol thin film evaporator, metamaterial reactor, Meituer filter, dimethyl sulfate cooler, liquid medicine filter, etc. The quantity and quality of the produced liquid medicine continue to improve, and the quality fully complies with the regulations of the Chinese Pharmacopoeia.

The Application of Titanium in Medical Devices

Titanium and titanium alloys have good corrosion resistance, and titanium is non-toxic and non-magnetic, making it a good material for medical devices. In the history of the development of surgical instruments, early surgical instruments were mostly made of carbon steel, but they were eliminated due to their performance not meeting clinical requirements after electroplating. The second generation includes austenitic, ferritic, and martensitic stainless steel surgical instruments, but chromium in the stainless steel composition is toxic, and the detached chrome layer has a certain impact on the human body. Therefore, the third generation - titanium surgical instruments - emerged. The lightweight nature of titanium makes it particularly suitable for microsurgical procedures. Titanium has corrosion resistance, good elasticity, and no deformation, and its surface quality is not affected by repeated cleaning and disinfection; Non magnetic properties that can eliminate the threat of damage to small and sensitive implanted electronic devices have made titanium surgical instruments increasingly widely used. At present, it has been used to make surgical blades, hemostatic forceps, scissors, electric bone drills, tweezers, and so on. Titanium vascular suture needles and sternal sutures are used in medical devices, as well as titanium filter plates for oxygen filters in cardiac surgical instruments. Titanium is used as electrodes in electrocardiographs and as incubators in vitro; The probe of the medical ultrasound grinder, the automatic controller of the blood transport box, and the titanium instruments used in ophthalmic surgery are currently in good condition.

Dental applications of titanium and titanium alloys

Due to its excellent corrosion resistance and human affinity, as well as considering metal allergies and specific strength, titanium is suitable for application in the field of dentistry. The metals used in dental surgery began with mercury amalgam and metal crowns in the 1920s. In the 1960s, gold, silver, and palladium alloys were mainly used. After the 1970s, stainless steel became a commonly used material for long-term and detachable orthodontic instruments. In the 1990s, titanium casting technology was promoted and applied. Dental use of titanium precision casting machines has the characteristics of high dimensional accuracy, no bubbles, and shrinkage. In metal materials used for human hard tissue repair, titanium's elastic modulus is very close to human tissue, which can reduce the mechanical incompatibility between metal implants and bone tissue. The thermal conductivity of titanium is at a relatively low level among all metal materials used in dental restoration. Low thermal conductivity can reduce thermal stimulation to the pulp of teeth with crowns, which is important for dental restoration. Titanium inlay, full crown, etc. have the function of protecting dental pulp and avoiding cold and hot stimulation. Dental titanium is mainly made of pure titanium in terms of material, but its strength is insufficient, difficult to grind, has poor wear resistance, is prone to casting defects, and has unstable quality. Titanium alloy has high strength, and Ti-6Al-4V alloy has a high market application rate. However, due to the harmful effects of metal V on the human body, Nb was used instead of V. Ti-6Al-7Nb alloy has been successfully developed, which has excellent corrosion resistance and is basically harmless to the human body. It also has other advantages such as strong plasticity and excellent grindability, and has been recognized by ASTM standards. Currently, superelastic Ti Ni alloys are being promoted for use in teeth straightening. Since the 1980s, developed countries have been studying the application of titanium in oral restoration. It was first used for dental implants, and later for denture supports, crowns, bridges, and orthodontic wires. Currently, titanium can be used as dental crowns, crowns, fixed bridges, porcelain bridges, bonded bridges, denture clasps, abutments, connecting devices, and reinforcing devices. Almost all metal components of dentures can be made of titanium. The research on titanium and titanium alloys has become a hot topic in the study of dental application alloys. Titanium alloy porcelain teeth can effectively restore the shape and function of teeth, with high strength, beautiful appearance, stable color, smooth surface, wear resistance, and corrosion resistance. It is a long-lasting restoration suitable for all fixed teeth, especially for those who are sensitive to nickel ions due to its good biocompatibility. It has been widely promoted and applied in dental restoration.