The metals used in dental surgery began with amalgam and metal crowns in the 1920s. In the 1960s, gold, silver, and palladium alloys were mainly used. After the 1970s, stainless steel became permanent and detachable instruments for orthodontics. The most commonly used material, titanium casting technology was promoted and applied in the 1990s. Dental use of titanium precision casting machine has the characteristics of high dimensional accuracy, no air bubbles and shrinkage cavities. Among the metal materials used for human hard tissue repair, the elastic modulus of titanium is the closest to human tissue, which can reduce the pressure on metal implants and bone. Mechanical incompatibility between tissues. The thermal conductivity of titanium is the lowest among all metal materials for dental restoration. The low thermal conductivity can reduce the thermal stimulation to the pulp of teeth with crowns, which is very important for dental restoration. Titanium inlays and full crowns can protect the dental pulp and avoid hot and cold stimulation. In terms of material, titanium used in dentistry is mostly pure titanium, but its strength is insufficient, difficult to grind, poor wear resistance, prone to casting defects and unstable quality. Titanium alloy has high strength, the most commonly used is Ti-6Al-4V alloy, but because metal V is harmful to human body, Nb is used instead of V, and Ti-6Al-7Nb alloy is successfully developed, which has excellent corrosion resistance and is It is basically harmless to the human body, and has other advantages such as strong plasticity and excellent abrasiveness, and has been approved by ASTM standards. At present, superelastic Ti-Ni alloys are being widely used in tooth straightening.
Since the 1980s, developed countries have begun to study the application of titanium in oral restorations, first for dental implants, and later for denture brackets, crown bridges and orthodontic wires. At present, titanium can be used as crowns and crown screws. , fixed bridges, porcelain bridges, bonded bridges, denture clasps, bases, connections and reinforcements, almost all metal parts of dentures can be made of titanium. The study of titanium and titanium alloys has become a hotspot in the study of alloys for dental applications. Titanium alloy porcelain teeth can restore the shape and function of the tooth body very well, and have high strength, beautiful appearance, stable color, smooth surface, wear resistance and corrosion resistance. It is a permanent restoration and is suitable for all fixed teeth. In particular, it has good biocompatibility and is more suitable for people who are sensitive to nickel ions. It has been widely used in tooth restoration.
