Have you noticed that many toothpastes now have expiration dates? This is because all toothpastes containing fluoride are regulated by the Food and Drug Administration, which now requires expiration dates. Up to that date, normally two years after manufacture, all the fluoride must be available to bind to tooth enamel, hardening it against the acid that causes cavities. Once that date is past, some of the fluoride ions may have bound with the caking agents into a salt or a crystal and thus aren’t available to bind to tooth enamel. Also, depending on the length of time and temperature of storage, the paste could separate so that an uneven amount of fluoride or flavoring agent is expressed at each squeeze. The viscosity might change and the toothpaste might not have the same consistency. So, check the date!
Sunday, December 21, 2008
Dr. Shapiro in the news
What Price Beauty: The Cost of Teeth-Whitening
I was recently interviewed for an article on teeth whitening on the website “mainstreet.” The article is a very good summary of bleaching options available. Check out the link: http://mainstreet.com/article/money/budgeting/what-price-beauty-cost-teeth-whitening to learn what I have to say about teeth whitening. I also have reprints in the office.
I just came back from two fabulous weekends of learning at The Rosenthal Institute’s Aesthetic Advantage Program at the NYU College of Dentistry. While I was there I studied the latest cosmetic techniques with the best dentists in the U.S. It was an inspiring experience.
Tongue map or not
Do you remember being taught that the tongue is a “map” divided into sections according to taste receptors? The tip of the tongue is for sweet, sides for sour and salty, and the back of the tongue for bitter. But recent studies show that the tongue map is wrong! We do know that there are at least five basic tastes: sweet, sour, salty, bitter and the recently discovered “umami”. Umami means “savory” in Japanese and can be detected in miso, soy sauce and other Asian foods, in particular those with monosodium glutamate. Scientists believe that there may be receptors for still other flavors. In a 2006 study in the journal Nature, scientists reported that receptors for the basic tastes are found in distinct cells and that these cells are not localized but spread throughout the tongue. Still other studies show that some parts of the tongue may be more sensitive to certain flavors and that there may be differences in how men and women detect sour, salty and bitter flavors.
Bisphenol-A, or BPA, and Dental Sealants
Bisphenol-A, or BPA, is widely used in making hard, clear plastic called polycarbonate. The National Toxicology Program, part of the Department of health and Human Services, has raised concerns about BPA, particularly over childhood exposure to traces that leach from polycarbonate baby bottles and the linings of infant formula cans. BPA has estrogenlike effects, and animal studies have suggested that exposure may accelerate puberty and raise a potential risk of cancer.
Traces of BPA have also been found in dental sealants. Some studies show that any exposure from the BPA in sealants is negligible and temporary. Other studies have found no detectable levels of BPA in most American-made sealants. Exposure to any BPA in sealants can be limited by polishing the tooth surface after the sealant is applied and rinsing at the end of the procedure. The study found that detectable amounts of BPA were not released from three products: Helioseal from Ivoclar Vivadent; Seal-Rite from the Pulpdent Corporation and Conseal from SDI.
Sealants prevent the growth of decay-causing bacteria in the grooves of molars and are a useful part of preventive dental practice. But concerned parents concerned about BPA exposure should ask their dentists what type of sealant they use and whether it has been tested for BPA. In my office I only use Helioseal from Ivoclar which does not release BPA according to both a March review article in the Journal of the Canadian Dental Association and a 2006 article in The Journal of the American Dental Association.
