Whiten Up: 6 Moves for Your Prettiest Smile Ever

Whitening: The 4 Most Common Questions

Can bleaching harm my teeth?
There are no studies that have proven that hydrogen or carbomide peroxide can cause permanent damage, because they maintain the enamel coating, according to Dr. Rosen. However, skip a product if it has an acid on the ingredients list (although most brands on the market don't include acids, it's still smart to check the label). "It etches away the superficial layer, leaving a chalky residue," explains Dr. Rosen.

Why do my teeth feel sensitive after whitening treatments?
Sensitivity can be caused by overuse of at-home products containing acids (like citric acid), which strip outer layers of enamel. "You can feel a slight zinging to a more intense pain, especially with hot or cold temperatures," explains Dr. Liechtung. This is normal and should diminish in 24 to 48 hours post-treatment, but if it lasts longer, consult a dentist.

How white is too white?
On the shade guide used by dentists, B1 is the whitest hue. However, due to overbleaching, new shades have been added that are considered whiter than what's naturally possible (OMI, OMII and OMIII). "Teeth in the OM category can stop reflecting light and appear gray," says Dr. Rosen. To reach this super-white level you'd have to have repetitive professional whitening, which would likely not be recommended by a dentist.

Can I change the color of my caps and veneers?
No, only your natural teeth can be lightened by bleaching agents. Because caps and veneers are artificial, peroxide can't change their hue, so dentists recommend that you seek a professional's advice instead of using over-the-counter kits. Dentists can usually bring caps and veneers back to their original shade through cleaning and polishing, helping your teeth to maintain a uniform look.