Cubic Zirconium…For Your Teeth?

Health Matters BY THOMAS JACKSON, DDS Cubic Zirconium…for Your Teeth?

PHOTO: THOMAS BALSAMO t may surprise you, but cubic zirconium (or The role of cubic zirconia I faux diamonds) aren’t just for your fingers Porcelain is also a very translucent material, but anymore. because the porcelain is only the cosmetic cover- They’re also for your teeth. ing to a metal core, the natural and desirable opti- Cubic zirconium (CZ) is formed when white cal properties seen in teeth are not replicated. This zirconium dioxide is heated to very high tempera- often leads to crowns in which the color is not tures. Cubic zirconium is extremely rare in nature, very lifelike, which are often referred to as being but it can be synthesized to a very hard, optically opaque. In addition, the blockage of light into the flawless, and colorless gemstone. These properties root causes the gum tissue to look dark and gray. also make the material very useful in dentistry. This is where zirconium dioxide becomes very Understanding porcelain relevant. When it is heated and stabilizing agents Porcelain or ceramic materials have revolution- are added, the strength properties can equal or ex- ized the field of cosmetic dentistry over the past ceed that of metal. Therefore, zirconia has been several decades. Prior to the advent of porcelains, developed to replace the metal in crowns and Thomas Jackson, DDS, is advanced-trained bridges. And because the material is white and dental fillings were routinely made of either gold in periodontics and periodontal prosthesis. Dr. transmits light, the optical pitfalls of metal can be or silver—not very cosmetic by today’s standards. Jackson is a board-certified periodontist and overcome. Porcelain, however, has optical properties that the founder of the Chicago Center for closely replicate the natural structures of the teeth, The role of gum tissue in appearance Cosmetic & Implant Dentistry. He lectures enamel, and dentin. The problem with porcelain, In cosmetic dentistry, the appearance of the gum nationally and internationally on issues though, is that like any glass, it is quite brittle; tissue can be just as important as the appear- relating to dental implants and cosmetics. many dental restorations would not be able to en- ance of the teeth in a beautiful smile. (I recently Dr. Jackson is an associate professor at devoted an entire column in Quintessential dure the stresses of chewing and grinding. Northwestern University’s Feinberg School To overcome this problem of weakness, den- Barrington to this topic). All too often I see peo- of Medicine, and he may be reached at tal porcelains have routinely been “baked” onto a ple who have metal-based porcelain crowns and 847-842-6900. rigid metal core or frame. In doing so, many of bridges, and it is quite obvious. Many times the il- the desirable cosmetic properties of porcelain are lusion of reality has not been maintained in these diminished. cases because the gum tissue appears dark and Dental enamel is a very translucent material, not in symmetry to the adjacent teeth. Zirconia and as light passes through it, it is reflected off of crowns avoid this pitfall, as the natural phenom- the dentin and back through the enamel, which enon of light transmitted through the root and produces the color that we see. Just as important, into the gingiva is not disturbed as it is in metal the light is transmitted into the root of the tooth, crowns. much like a fiber-optic cable. As the light passes Understanding porcelain into the root, it then reflects into the surrounding So who would have guessed that the same cubic gum tissue, allowing for the pink of the gingiva to zirconium sold in jewelry stores would be even be illuminated. more useful in your mouth? After all, people look at your smile long before they look at your fingers. And while this mineral may be a “faux diamond,” it’s the real thing when it comes to producing a beautiful smile.

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