In dental industry, titanium is used as a superior material because its good capacities. But there is something important to be process during the manufacturing.
In high temperature titanium is apt to react with elements of O, H and N in the atmosphere and with elements of Si, Al in the raw material. This reaction will bring a dirty surface on the casting which increases its hardness and brittleness, decreases its flexibility and plasticity.
Because of its low density, fluid titanium has weak inertia as it flows. And this brings low flowing in the casting. The difference of temperature between casting and mold is a bit great, the temperature drops fast, so casting must be done under protective situation. These factors would result in gas cavities and other flaws on the surface and inside of the titanium castings.
The flaws are affect the quality of castings very much.So it is much more important to process titanium casting surface than other dental alloy. Because of the special capacities of titanium, such as low conducting of heat and electricity, hardness of surface, oxidizing etc, it is difficult to process titanium surface. General methods of surface processing can not bring good effect, so special methods must be applied.
The purpose of titanium surface processing is not just making it smooth. The process can reduce conglutination of food and fungus, maintain the balance of nature in the mouth. The most important this improves the capacities in corrosion, friction and applicability.