ABSTRACT
Recently, articial teeth made of plastics and ceramics have seen growing application in elderly patients, especially in developed countries. There are nearly one million pieces of articial teeth manufactured in Japan (Ministry of Health, Labor and Welfare in Japan, 2010), and the total number worldwide is reported to be 3 billion. Articial teeth should be harmless to human health and designed to harmonize with the tissues in the oral cavity. They must also have the functional properties for chewing. Intrinsically, plastic teeth have more harmonized properties than ceramic teeth, and hence the percentage of plastic teeth (80%) in Japan is expected to increase in the future.
