Dental Ceramics: What Is This Stuff Anyway? J. Robert Kelly J Am Dent Assoc 2008;139;4S-7S

The following resources related to this article are available online at jada.ada.org ( this information is current as of January 8, 2011 ):
Updated information and services including high-resolution figures, can be found in the online version of this article at: http://jada.ada.org/cgi/content/full/139/suppl_4/4S Information about obtaining reprints of this article or about permission to reproduce this article in whole or in part can be found at: http://www.ada.org/prof/resources/pubs/jada/permissions.asp Downloaded from jada.ada.org on January 8, 2011

© 2011 American Dental Association. The sponsor and its products are not endorsed by …ver más…

139 http://jada.ada.org September 2008

make the restoration. Dentists can apply these concepts directly to gain insights into two general facts regarding dental ceramics: d Highly esthetic dental ceramics have a high glass content, and higher-strength substructure ceramics generally are crystalline. d The history of the development of substructure ceramics involves an increase in crystalline content ranging from approximately 55 percent crystalline to fully polycrystalline. Predominantly glass. Dental ceramics that best mimic the optical properties of enamel and dentin have a high glass content. Manufacturers use small amounts of filler particles to control optical effects such as opalescence, color and opacity. Most veneering materials come paired with their appropriate substructure ceramic, so it makes little sense to introduce them according to trade name (which is why I have not included them in Figure 2). I discuss predominantly glassbased ceramics in more detail elsewhere.1 Particle-filled glass. Manufacturers add filler particles to the base glass composition to improve mechanical properties, such as strength and thermal expansion and contraction behavior. These fillers usually