The movie screen is filled with a weird image of a gaping mouth, with dental retractors and teeth gleaming under an eerie white light. The focus pulls away and we realize the mouth belongs to George Clooney in the 2003 movie Intolerable Cruelty. And George, as shark-like divorce attorney Miles Massey, is having his teeth power-whitened.
Movie stars, celebrities (and high-profile divorce attorneys) are not the only people anxious to have gleaming, white teeth. An estimated ten million Americans buy teeth whitening products and services this year, to the tune of $1.7 billion. If you are one of them, be glad that you’re whitening your teeth in the 21st century. It is believed that the ancient Romans used human urine to strengthen and whiten teeth. Since the mid-1800s, dentists have been using hydrogen peroxide to bleach teeth. By the 1980s, teeth whitening became one of the most common dental treatments.
Sources of stains
Lots of things can stain your teeth, such as coffee and tea, grape juice, red wine or other colored beverages. Nicotine from tobacco products are notorious for turning teeth yellow. Some diseases and normal aging will discolor teeth. Also, medications, such as tetracycline can stain teeth; so can certain dental substances, such as excessive fluoride or chlorhexidine used as an antibacterial rinse.
The first layer on a tooth is the enamel, which is clear and transparent. The next layer is the dentin, a spongy substance that is normally yellowish, but can be gray, brown or even black. In teeth whitening, hydrogen peroxide opens the pores of the enamel on the tooth in order to penetrate the layer of dentin and bleach out the color. Hydrogen peroxide is the primary bleaching agent. Some treatments use carbamide peroxide, which is essentially hydrogen peroxide that has an added urea molecule.
Professional and OTC whitening
Not surprisingly, the most effective teeth whitening is performed by professional dentists. Dentists commonly use hydrogen peroxide in concentrations ranging from 15 percent to 35 percent. Sometimes treatments will include light or lasers to accelerate the whitening process.
You can also ask your dentist for an at-home treatment kit. This may include custom-made trays that fit your teeth to hold a special bleaching solution in contact with the enamel surface. The at-home kit option will include the cost of the dental office visit, but some dentists will provide the kits for free as an incentive for new patients.
A wide array of teeth-whitening products are available over the counter. Whitening strips come in varying strengths, and whitening toothpastes or rinses can help keep treated teeth whiter for a little while longer. Whitening toothpastes contain polishing or chemical agents that remove stains without bleaching.
Safety and sensitivity
Teeth whitening is generally considered safe, but there are at least two major drawbacks from teeth whitening (other than cost, of course). First, opening the pores, or dentinal tubules, in the teeth with hydrogen peroxide can result in pain and sensitivity. Sensitive formula toothpastes, which remineralize the enamel and close up the tubules, may be helpful.
The other drawback is that many people complain about irritated gums following whitening treatment. No wonder. The hydrogen peroxide can be extremely irritating or even deadly to oral cells. Scientists at Texas A&M Health Science Center Baylor College of Dentistry (BCD) in Dallas, Texas did some experiments with oral cells—the cells that make up the ligaments holding teeth in place and the cells that become gingival or gum tissue. They exposed the cells to toxic substances including nicotine, alcohol, and hydrogen peroxide. At high concentrations, the oral cells died. At lower concentrations, they just ceased to multiply as needed for growth and healing.
Then the researchers exposed the oral cells to the toxins again, but this time they treated them with different concentrations and combinations of antioxidants including phloretin and ferulic acid. They found that the antioxidants significantly counteracted the effects of hydrogen peroxide by increasing the cell viability and survival. They also noted that antioxidants decreased the production of reactive oxygen species (ROS), or free radicals. In other words, the combinations of antioxidants protected these oral cells from the free radical damage caused by hydrogen peroxide.
The same antioxidants, phloretin and ferulic acid, are the basis of PerioSciences AO ProVantage dental gel and AO ProRinse mouth wash and AO ProVantage BLAST. These products bring the power of antioxidants to soothe gums and promote healthy-looking oral tissues. Fresh breath and a clean feeling in the mouth are great, too.
Back in 2003, Miles Massey (and George Clooney, for that matter) walked out of the dentist’s office with gleaming white teeth and tender gums. Today, anyone can walk out with whiter teeth, armed with dental antioxidants for an even healthier smile.