These days, celebrities aren’t the only ones flashing extra-pearly whites. Teeth whitening has become more affordable and accessible for everyone, with both professional whitening services and over-the-counter kits on the rise. But is whitening really safe for your teeth? Do dentists recommend it?
“Tooth whitening certainly has its place in the dental world,” says Dr. Isabelle Chase, assistant professor of developmental biology in pediatric dentistry at Harvard School of Dental Medicine. “If it’s done with a health professional and it’s closely monitored, it certainly can be safe.”
We spoke with dental experts about the basics of safe teeth whitening so you can be sure you’re protecting your smile while making it brighter.
The rise of whiter smiles
Teeth whitening is a rapidly-expanding industry: Market studies have pinned the global value of teeth whitening products and services at over $6 billion and growing fast. It’s not hard to guess why: The rise of social media means more people are sharing photos of their smiles, and some people are noticing imperfections they’d like to fix. A 2012 survey from the American Academy of Cosmetic Dentistry found respondents’ greatest concern for their smiles was “whiter and brighter teeth.”
At the same time, there’s been a large increase in sales of over-the-counter teeth whitening kits, and more dental offices are offering in-house whitening services.
Teeth whitening options—with or without the dentist
Teeth whiteners fall into two categories: The first are whitening toothpastes, sold over the counter, which use mild abrasives that scrub the teeth to remove surface stains. Some also contain blue covarine, a chemical that adheres to the dental surface and makes teeth appear whiter.
The American Dental Association recommends selecting whitening toothpastes that have earned the ADA Seal of Acceptance, which means they have extra polishing agents for more effective stain removal.
The second and more extreme whitening option is bleach. Treatments include in-office bleaching, at-home bleaching designed by a dentist or over-the-counter bleaching kits. Bleach whiteners use one of two chemicals: carbamide peroxide or hydrogen peroxide. The major difference between the two is the concentration of the solution and the length of time the bleach stays on the teeth.
“For a really low-level bleach, you’ll sleep with the tray overnight,” Chase says. “With a high-level bleach, you’d only use it for twenty minutes at a time.”
Whether supervised bleaching is done in the office or at home, the process is similar: The dental team takes a model of your mouth to fabricate custom trays that fit snugly over your teeth. The trays are filled with the proper amount of bleaching solution as determined by the doctor, and you keep them on your teeth for a given amount of time.
Your provider may also place a protective gel on your gums to prevent irritation or give you a gel to apply at home. Because in-office treatments use a higher bleach concentration, they work faster and generally require only one visit, whereas at-home bleaching could take a few days or weeks.
Over-the-counter bleaching kits are not supervised by dentists. They contain much lower concentrations of bleach and take longer to work. These kits use either topical strips or generic trays, which are not lab-fabricated for your teeth and won’t fit as well, Chase says.
“There are higher rates of gingival inflammation and irritation and a greater chance you’re going to swallow the bleaching products” with at-home kits, Chase says. The ADA gives its seal of approval to a few over-the-counter bleaching kits, but they recommend conferring with your dentist before using them.
Some people experience tooth sensitivity after bleaching treatments, whether doctor-supervised or not. Overuse or improper use of whiteners can also damage the enamel or cause inflammation of the dental nerve. “Whitening does have to be monitored closely,” Chase says.
While the bleaching agents used in dental whitening haven’t changed much in the past few decades, some dentists are now using light activation to speed up the process.
Different kinds of “curing lights” can accelerate whitening treatment, from LED to plasma arches to lasers. But research is mixed on the effectiveness of curing lights: A 2014 study summarizing recent research did not find that light activators accelerated the bleaching process, nor did they achieve better results than bleaching alone. Chase says that, in her office at least, bleaching treatments without a curing light are still the norm.
Kids, orthodontics and whitening
As a pediatric dentist, Chase gets a lot of questions about whether whitening is safe for kids and teens. There isn’t an official recommended age to start whitening, but she doesn’t offer it for children younger than fourteen: “Below that age, the nerve in the tooth is quite large, so you have potentially higher risk of damage to the teeth,” Chase says.
For children who need braces, she recommends finishing orthodontic treatment before whitening.
“Usually it’s around the age 14 or 15 that the braces come off, and then it’s certainly safe to do it,” she says.
Orthodontists also perform a lot of teeth whitening: A 2013 study found that 88.8% of orthodontists surveyed had patients who requested whitening, and 32.8% of orthodontists provided whitening in their offices.
Dr. Oleg Drut, chief clinical officer of Diamond Braces, an orthodontic practice with offices in the New York City metro region, says he gets questions about whitening all the time, especially from patients with removable aligners like Invisalign.
“Patients with aligners are concerned about the attachments on the teeth,” he says, referring to the small, clear attachments affixed to teeth to hold removable aligners in place. Drut says the whitening solution will reach beneath the attachments without staining them. “It’s not an issue at all.”
For patients with braces, Drut agrees with Chase that it’s best to wait on whitening until after the braces come off.
“With braces, plaque can develop underneath the brackets, and clean teeth are more difficult to maintain.” But patients straightening their teeth with removable aligner trays like Invisalign can start their teeth whitening at any time.
Tooth sensitivity or gum irritation are two of the most common side effects of whitening for patients of all ages, but Drut assures his patients that teeth whitening is safe.
“Some patients are more sensitive than others,” he says. But when whitening is done correctly, “There’s no research showing that the treatment damages the enamel.”