Titanium is suitable for dental application because of its excellent corrosion resistance and human affinity. The metal used in dental surgery started from amalgam and metal crowns in the 1920s, gold, silver and palladium alloys were mainly used in the 1960s, stainless steel became the most commonly used material for permanent and detachable orthodontic instruments after the 1970s, and titanium casting technology was popularized and applied in the 1990s.In the metal materials used for repairing hard tissue of human body, 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 the metal materials used for dental restoration. Low thermal conductivity can reduce the thermal stimulation of the pulp of teeth with crowns, which is very important for dental restoration. Titanium inlaying and full crown can protect the pulp and avoid heat and cold stimulation. Dental titanium in the material, mostly pure titanium, but its strength is insufficient, difficult to grind, there is poor wear resistance, easy to produce casting defects and quality instability.Ti-6al-4v alloy is the most commonly used alloy with high strength, but since the metal V is harmful to human body, Nb is used instead of V, and ti-6al-7nb alloy has been successfully developed, which has excellent corrosion resistance, basically harmless to human body, strong plasticity, excellent abrasiveness and other advantages, and has been recognized by ASTM standard. At present, 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 of 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.
