The mouth cavity is a ecosystem environment effected by biochemistry and electricity chemistry etc. Be one of the human body four greatest germs databases, the microorganism is mutually exist extensive and complicated mutually check with the human body, helping maintenance the balance of the ecosystem environment. With the using of dental prosthetic restoration, this balance is destructed. It is why there are more Gingivitis, dental caries and denture stomatitis with the person wearing denture. These reques...