Teeth whitening is the most common cosmetic procedure that dentists perform.
That’s because everyone wants a bright, white, attention-grabbing smile. An estimated 10 million Americans will spend over 1.7 billion dollars this year alone on whitening services and products. Before we can get into the details of how teeth whitening works it’s important to understand why you might need this in the first place. Stains.
How teeth get discolored
Your teeth are made up of an inner layer called dentin and an outer layer enamel. Enamel is hard and shiny but is easily stained. Food, and other substances build up on your teeth in the form of a tiny particle layer call a “pellicle film.” Brushing your teeth can take some of it off and whitening toothpastes are designed to work even harder on enamel. Beyond good oral hygiene a dentist can clean away this film, through teeth cleanings.
The pellicle layer gradually gives way to discoloration in the enamel layer, discoloring it slightly. Over the years, that adds up, and that’s why many adults eventually seek out teeth whitening treatments.
Common causes for stains
- Foods/Drinks: Coffee, tea, soda, wines and certain foods ( potatoes, cherries, blueberries)
- Chewing tobacco and smoking
- Poor Dental Hygiene
- Medicine: Antihistamines, antidepressants and high blood pressure pills.
- Dental Work: silver amalgam restorations can produce a grayish-black color on the teeth.
- Age: As you get older, the outer layer of enamel on your teeth wears away, revealing the dentin’s natural, yellow color.
- Genetics: Some people have whiter, healthier teeth
- Location: Excessive fluoride from environmental sources, such as high fluoride levels in drinking water.
- Medical Treatments: Certain treatments can adversely affect the color of enamel and dentin layers. Chemotherapy and head and neck radiation are two examples.
So how does teeth whitening work?
Over the counter teeth whiteners use bleaching chemicals to get down into the tooth enamel and set off a chemical reaction that breaks apart the staining compounds. Most tooth whiteners use one of two chemical agents: carbamide peroxide or hydrogen peroxide (the same stuff that will bleach your hair). When used in the mouth, carbamide peroxide breaks down into hydrogen peroxide and urea, with hydrogen peroxide being the active whitening ingredient. Its also important to point out that you should have your teeth professionally cleaned and checked before going with this method.
In-office treatments will use more powerful controlled concentration of the peroxide, and a special high-intensity light that accelerates the bleaching, each being tailored to a particular patient. Before the tooth whitening treatment, the dentist will clean the teeth, fill cavities, and make sure your gums are healthy. They then place a hydrogen peroxide paste on the teeth for several minutes, rinses it off, and can apply it several more times. The procedure can achieve about four to six shades of whitening after only one 40-minute treatment.
In-home treatments are another option. The dentist will take a mold of your mouth and make custom mouth trays. The patient will put a thin layer of whitening gel into the tray and wear it for about 2 hours a day or while sleeping. Most whitening occurs in one to two weeks.