Since the discovery of titanium, titanium is known as the "magic metal" because of its specific strength (tensile strength/density) and other superior properties and is widely used in aerospace, machinery, electricity, medical, and other fields. Titanium: silver-white rare light metal, atomic number 22, density 4.51g/CM2. Because titanium has no sensitization, carcinogenic or teratogenic phenomena in contact with the human body, it can be well combined with bone tissue, epithelium, and connective tissue, so it is the metal material with the best biocompatibility, and is known as "the most human-friendly metal material." Metal". Medical titanium metal is the most widely used metal implanted in the human body in modern medicine, accounting for more than 80%; medical pure titanium has also achieved good results in the field of oral dentures.
Titanium has the following good physical and chemical properties:
1. The passive film on the surface of pure titanium metal has a strong resistance to acid corrosion, so pure titanium dentures are not easy to corrode. The excellent mechanical properties of pure titanium are also the first choice for making dentures: the elastic modulus is low and has a memory function, so it is very advantageous to use pure titanium as a rigid support ring. And will not damage the abutment.
2. Low density: about 1/4 of gold; 1/2 of cobalt-chromium alloy; therefore, pure titanium dentures are much lighter than dentures made of other materials. The same volume of a steel tray, its weight is less than half of ordinary cobalt-chromium alloy, which can greatly reduce the burden on oral soft tissue;
3. Low thermal conductivity: only 1/17 of gold. Therefore, pure titanium porcelain teeth can effectively protect the pulp tissue from the external hot and cold acid stimulation;
4. Small linear shrinkage: 1.75%, lower than gold alloy and cobalt-chromium alloy, has excellent suitability and high casting precision, so pure titanium porcelain teeth have high edge adhesion, which can effectively prevent porcelain crowns The occurrence of dental caries;
5. X-ray is semi-resistive: X-ray can check the dental tissue in titanium crowns, so the health of the teeth can be diagnosed without breaking the crown. In addition, pure titanium porcelain teeth will not affect the examination of head CT;
6. Titanium metal is non-magnetic: pure titanium series dentures will not be magnetized in the magnetic field, which is very important; pure titanium porcelain teeth and all-ceramic teeth are the only two fixed restorations that will not affect the cranial MRI examination ;
Application of medical titanium in the oral cavity:
The researchers tested the device in people with unilateral deafness. A study confirmed that the device was comfortable to wear, harmless to teeth, and improved language comprehension in noisy environments. The researchers plan to submit their findings to the U.S. Food and Drug Administration and apply for licensure as early as 2010. If all goes according to plan, the device will hit the market later in 2010 and will benefit millions of deaf people by then. People who are unilaterally deaf have difficulty judging the exact source of the sound, they are very dangerous when crossing the street, and they have difficulty listening to other people's conversations in a noisy room. The San Mateo Tinnitus Research Center in California has created a small device that wraps around teeth that picks up sound information from tiny microphones placed in deaf ears and converts them into vibration signals. The vibration signal is transmitted to the cochlea of the healthy ear through the teeth and jaw, and then to the brain to produce stereoscopic hearing. This kind of "bone conduction" auditory transmission is the way normal people hear their own voices. Some hearing aids also transmit the sound to the cochlea through bone conduction, but some need to drill the skull to place titanium rods, and some need to wear cumbersome earphones. The conventional hearing aid simply amplifies the air-conducted sound and then transmits it into the ear.
