Pearly whites may have a price.
According to the American Academy of Cosmetic Dentistry, teeth whitening is expected to become a $ 7.4 billion industry by 2024, with Americans spending just $ 1.4 billion in over-the-counter whiteners to bleach stains of cigarettes, red wine, coffee and natural aging. .
But preliminary research presented at the American Society of Biochemistry and Molecular Biology's annual meeting this week suggests that these bleaching strips could damage teeth under the surface.
Our teeth consist of three layers: the outer layer of white enamel; the underlying dentin layer composed of proteins (i.e., collagen); and the pulp in the center that houses the nerves, blood vessels, and the connective that binds the tooth to our gums. And this latest research has revealed that hydrogen peroxide that serves as an active ingredient in bleaching products could adversely affect this layer of protein-rich dentin.
The study, led by Kelly Keenan, an associate professor of chemistry at Stockton University, processed extracted human teeth (cadavers) with bleach strips, following the manufacturer's instructions to leave them for one hour. The researchers also immersed the teeth in artificial saliva and washed them, to simulate what the teeth feel in a human mouth.
Then they followed the level of collagen and other proteins remaining in the dentin layer of the bleached teeth, and compared it to a control group of unbleached teeth, as well as to another group of whitened teeth three times.
They found that whitened teeth with tapes once had less collagen and other proteins than untreated teeth; the proteins have been converted into smaller fragments. And those whitened three times had even smaller amounts of collagen.
"Our results show that treatment with hydrogen peroxide concentrations similar to those found in whitening strips is enough to remove the original collagen protein," Keenan said in a statement.
There are some limitations; This was not a peer-reviewed study and live teeth in the mouth respond differently to bleaching agents than extracted teeth.
"These teeth were probably dehydrated and had a different composition than the teeth in a living person," MarketWatch told the author and orthodontist Dr. Ana Castilla.
"Nevertheless, it's good to always keep an eye on what research shows about the products we commonly use."
The teeth whitening products are considered safe by the American Dental Association and according to the latest research, when the user follows the manufacturer's instructions and does not leave the bleaching agent too long, do not swallow it etc.
"Teeth whitening is the most requested service in many dental practices across the country …. and we are confident that these products are safe and effective for all tooth tissues, "said MarketWatch's Dr. Edmond Hewlett, spokesperson for the American Dental Association and dean of the UCLA School of Dentistry.
But the science shows that the strips have some side effects, most often increased sensitivity of the teeth and mild irritation of the gums, which can last several days and be very painful, especially if the whitening agent enters a cavity or if your gums are already inflamed. or bleeding from gum disease.
And overuse can also damage teeth by dehydration and demineralization.
"You can advise a patient who uses it every day to try every other day. There are a number of toothpastes on the market that contain ingredients that help improve tooth sensitivity. We will ask patients to use them for about a week, Dr. Hewlett said.
"But once the whitening product is used, the teeth (sensitivity) must return to normal."
Dentists with whom MarketWatch spoke have recommended professional whitening (about $ 650 or more) to mitigate the risks associated with improper use.
"The best is to whiten under the supervision of your dentist. If you do not monitor the whitening strips and do not place them properly, you can burn your gums or create white spots on your gums, "said Dr. Castilla.
In addition, accidental ingestion of the bleaching agent can irritate your throat and cause nausea or irritation of the stomach.
"Ingestion of materials is the biggest problem," said Dr. Adam Scot Harwood, Endodontics Expert and Dental Specialist at MarketWatch. "Some patients have stomach or bowel problems after ingesting this material for a long time."
These home-made whitening strips, like Procter & Gamble PG's Crest 3D White Luxury Professional Effects tape ($ 54.99) or Walgreens Whitening Wraps ($ 13.99) can also munch on your wallet – they're not are not as effective for everyone.
For example, porcelain veneers, crowns, bridges, dental implants or cosmetic binders on teeth will not whiten. As a result, they will stay darker and give an uneven smile of color.
Neglected teeth that have not been brushed regularly, or cleaned annually during a dental examination, will not respond as well to bleaching procedures. And gray teeth or internal stains due to taking antibiotic tetracycline, or too much fluoride during childhood, are also impossible to eliminate with teeth whitening products.
In addition, you should refrain from contaminating culprits such as cigarettes, coffee and red wine for a few weeks after your treatment – not just a few hours – to keep that smile radiant.
"When you whiten teeth, you temporarily increase the porosity of the enamel (so that the whitening agent can reach the discolored molecules in your teeth), so you are more likely to stain your teeth right after that. whitening, "explained Dr. Castilla.
The bottom line: The whitening strips are probably safe, but talk to your dentist before trying whitening products. Together, you can determine if you are prone to painful sensitivity to the teeth or gums, as well as whether home treatment will be effective on your spots.
And when you buy whitening products, choose those that bear the seal of acceptance of the American Dental Association, which means they have been evaluated by an independent group of dentists.