By: Beth Walsh for Dental1The majority of dental procedures – about 70 percent – involve replacements to existing repairs. Now, researchers may be able to improve that rate even further.
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Dental procedures that involve replacement of existing repairs cost $5 billion a year in the United States.
Preventing cavities is much less expensive than repairing them. Ninety percent of cavities are preventable. However, 20 percent of kids under 5 have cavities in their baby teeth and at least half of children in third grade have one cavity or more.
To both prevent cavities and help fillings last, visit your dentist for cleanings twice a year, brush with a fluoride toothpaste and floss twice a day. Cut down on the amount of sugary foods and drinks you consume to reduce the number of times your teeth are subjected to acid. Chewing sugar free gum for ten minutes after a meal increases the saliva flow and helps to neutralize any acids which have been formed as a result of eating sugary foods. |
Scientists at the American Dental Association's Paffenbarger Research Center, a joint research program at the National Institute of Standards and Technology, have shown that use of nanotechnology could produce tooth restorations that are stronger than the decay-fighting fillings now available. Fillings may crack as a result of biting, chewing and teeth grinding. Secondary decay can develop, which causes the filling to bind to the tooth. Nanotechnology may also be more effective than traditional methods at preventing secondary decay.
Currently, dentists often use a composite resin filling. This filling is created by mixing pure liquid resin with a powder that contains coloring for a natural appearance, as well as reinforcement and other materials. The resulting paste is packed into the cavity and the tooth is then illuminated with a light that causes the paste to polymerize and harden.
Decay-fighting composite fillings have an additive that steadily releases calcium and phosphate ions. These ions strengthen the crystal structure of the tooth and protect it from the decay-causing acid produced by bacteria in the mouth. The ion-releasing compounds used today are structurally weak, even weakening the filling as a whole. To address this problem, Paffenbarger researchers have devised a spray-drying technique that yields particles of several such compounds, one of which is dicalcium phosphate anhydrous, or DCPA. DCPA is approximately 50 nanometers across – 20 times smaller than the one-micrometer particles in conventional DCPA powder. Because these nanoscale particles have a much higher surface to volume ratio, they are much more effective at releasing ions. As a result, less of the material is required to produce the same effect; thus, the filling resin has more reinforcing fibers that can strengthen the final filling.
In addition, Paffenbarger researchers have developed nanoscale silica-fused fibers that produce a composite resin nearly twice as strong as the currently available commercial variety.
Huakun Xu, PhD, senior project leader at the research center, said that the new nanocomposites are still in the research stage. A patent application was filed more than a year ago. Once a patent is issued, a manufacturer has to agree to license the product and take the product through Food and Drug Administration testing process. At that point, they will be available to consumers.
