Why go to the dentist for that blinding white smile when the drugstore is around the block and wallet-friendly? After all, right there on Aisle 8 sit hundreds of Advanced Tooth Whitening Systems, each one more advanced than the next. Red-carpet smiles are yours from the comfort of your couch.

Experts at The University of Texas Health Science Center at Houston (UTHealth) School of Dentistry caution us about drugstore dentistry: Until you’ve talked to your dentist, don’t try this at home. It could save your teeth — and the rest of you, too.

Bite the bullet — call your dentist

Joe C. Ontiveros, DDS, MS, UT Dentists provider and director of esthetic dentistry at UTHealth School of Dentistry, sheds light on the controversy and concerns dentists have about over-the-counter (OTC) whitening products and their possible connection to oral cancers and other serious oral diseases. The concern about these products stems from hydrogen peroxide’s known capability of producing free radicals, which have been implicated in various biological consequences, Ontiveros says.

“Much of the safety concerns with home-use bleaching originate from the peroxide that is released from the products, especially known toxicity of free radicals,” explains Ontiveros. “The reaction and potential damage in the cells is by the free radicals. That’s what’s believed to be the major mechanism responsible for the toxicity of peroxide.”

Everyone should have a professional dental exam prior to bleaching, Ontiveros adds, regardless of whether you’re bleaching your teeth at home or going to a dentist.

“The dentist can determine the cause of discolored teeth, screen for periodontal disease, check for decay, assess the condition of existing restorations and identify any exposed roots,” he says.

If you have tooth or gum sensitivity, your tooth roots might be exposed from receding gums. Bleaching can make it worse.

The concentration of certain chemicals in tooth whiteners also can vary from product to product, causing potential damage and susceptibility to cancers and disease. While not much has changed in OTC teeth whitening products over the last several years, one thing that’s on the rise is the concentration of hydrogen peroxide. Ontiveros says companies are beginning to increase peroxide’s concentration, in order to recommend a shorter wear time.

“In my opinion, when you start increasing the concentration, this decreases the safety because you’re exposing yourself to a greater risk when you’re using a higher concentration without certain precautions,” he notes.

However, individuals can be protected from overexposure to these chemicals by a dentist who can monitor the levels and adjust the whitening procedure appropriately.

Kathy O’Keefe, DDS, MS, former adjunct professor at UTHealth School of Dentistry, acknowledges that one of the possible dangers to the at-home systems are the one-size-fits-all bleaching trays that simply cannot keep the bleaching product from leaking into the mouth.

“Bleaching trays that dentists fabricate are made from accurate impressions of the patient’s upper and lower teeth; therefore, there is usually no leakage from the trays to the oral cavity,” she explains. “This is a much more well-controlled system.”

Custom trays made by your dentist also allow for tailoring the bleaching process, O’Keefe adds.

“If one or two teeth need more bleaching time, or if the lower teeth don’t bleach as quickly as the upper teeth, the patient can place bleach in the areas of the tray that need specific attention,” she says.

Another reason to make that dental appointment is that some people will not get that blinding white smile no matter what product they use — particularly those with intrinsic staining, or deep staining, that runs through the entire tooth. An antibiotic like tetracycline or some other medication may cause intrinsic staining, Ontiveros explains.

In those cases, a type of custom tray designed to use long term is one course of treatment, as are porcelain veneers, crafted by an esthetic dentist. And those patients with veneers cannot use OTC bleaching products because the chemicals will change the surface of the veneer. Teeth whitening products also cannot change the color of a veneer.

Ontiveros cautions patients to be aware of existing tooth-colored fillings and/or previous dental bonding procedures. Just like the veneer, he says, the bonding or the tooth-colored filling will not change color.

“If you’re using a bleaching product independent of your dentist, be sure to inform your dentist before you’re going to have a new filling because the bleach may cause your new filling to leak, or even worse, to fall out,” Ontiveros adds. “These bleach products will interfere with the bond or adhesive that we use when we place these new fillings. In other words, we can’t put a new filling on teeth that have recently been bleached.”

Addicted to whiter white

Many consumers’ obsession with white teeth has caused them to become addicted to bleaching. “We are now seeing patients that we would classify as the non-academic term, 'bleachorexics,'” Ontiveros says. Bleachorexia is a term that dentists use to describe an addictive obsession with teeth bleaching to the point that it affects dental health. This obsession can lead to the abuse of over-the-counter products.

“Some patients become psychologically addicted to bleaching, never thinking their teeth are white enough,” O’Keefe says. “The dentist can control this by limiting the amount of prescription strength bleach they sell to patients.”

Her office has such a system in place that helps to prevent such behavior.

“Typically, one or two boxes of bleach are dispensed with new bleaching trays,” O’Keefe says. “If patients want more bleach, they can purchase more, with our permission.”

Brown teeth and first impressions

Tooth whitening is recommended by job recruiters, dating services, meddling grandmothers and both men’s and women’s magazines as the easiest, most cost-effective way to make one personal change that will catapult a first, second and third impression.

“The American Academy of Cosmetic Dentistry completed a study regarding tooth brightness and appearance. An overwhelming majority (90 percent) of those surveyed viewed people with whiter teeth as healthier and more attractive,” Ontiveros says. “Many people feel this may influence professional advancement and personal relationships.”

In fact, further studies by the American Academy of Cosmetic Dentistry show that 96 percent of adults believe an attractive smile makes a person more appealing to the opposite sex, and 74 percent of adults feel an unattractive smile can hurt a person’s chances for career success.

How white is too white?

The emerging popularity of teeth whitening has sparked changes in the dental industry. The American Dental Association recently has changed its standards for monitoring bleaching from a 16-step color scale (Classical Shade Guide)that has been used in dentistry for more than 50 years, to a new 29-step color scale (Bleachedguide 3D Master) developed by UTHealth School of Dentistry associate professor Rade Paravina, DDS, MS, PhD. Furthermore, specialized color instruments are now being used in the dental office that can provide objective digital measurements for monitoring bleaching. These changes have occurred out of the widespread increase in tooth whitening and the necessity to measure tooth color beyond what traditionally has been considered the lightest of the natural shades.  

Ontiveros is considered a key opinion leader in the aesthetic materials area of expertise which includes bleaching. He says that it is not uncommon for consumers to over-bleach their teeth. “That’s something that is starting to become a concern to some of the health-conscious manufacturers,” he says. Some companies have awareness campaigns that urge users to consult a dentist before using whitening products.

While on the quest for whiter teeth, it’s important for consumers to be aware of the numerous risks associated with over-bleaching. In addition to tooth enamel erosion, hypersensitivity can occur, making teeth sensitive to hot and cold. Bleach can also cause nausea and irritation on the gums, palate and throat. The side effects associated with these risks usually subside once a patient discontinues bleach usage.

Bleaching is safe... the right way

Ontiveros makes it clear that the general idea of whitening your teeth to remove natural discoloration is safe and can be effective. In fact, a large number of clinical trials in dental patients over the last 20 years have demonstrated the safety of bleaching. That is, he stresses, when it’s dentist-supervised bleaching.

“Hydrogen peroxide exposure from tooth whiteners is limited to the oral cavity and is incapable of reaching systemic levels,” he says. “There are certain enzymes, including catalase and peroxidases, which exist widely in the body fluids, tissues and organs that effectively metabolize hydrogen peroxide. In fact, the enzymes in our saliva, namely peroxidases, have been suggested to be the body’s most important and effective defense against potential side effects or adverse effects of hydrogen peroxide.”

Although a direct connection between oral cancers and over-the-counter tooth whitening has not been made, enough factors are present to have researchers looking for more.

In the meantime, ask your dentist for bleaching advice before you start a regimen.