Time to Spring Clean your smile? When you want to re-sparkle your smile you’ve basically got two options: buying a drugstore whitening product or having your dentist do it. 
Regardless of which option you choose, the whitening process involves peroxide-based bleaching agents. The biggest difference is in the amounts of bleaching agents that they use. Drugstore whitening products contain anywhere from 3%-20% peroxide in their formulas. The dentist’s formula will have from 15%-45% peroxide in their whitening agents.
Both options have their advantages and disadvantages, but talk to your dentist. You may not have great results, especially if you have crowns or bondings. These don’t whiten with bleach. Tooth-whitening works best for people with yellow teeth and is less effective for people with brown teeth. If your teeth are gray or purple, tooth bleaching probably won’t work at all. Also, bleaching can make teeth sensitive — or be uncomfortable for people who already have sensitive teeth.
Dentist Whitening
Teeth whitening done by your dentist can work better. The solution they use is much stronger than at-home kits, and dentists often use heat, light, or a combination of the two to speed and intensify the process.
The most dramatic results usually take several office visits, but some dentists use techniques that can be done in a single appointment.
At-Home Options
- Strips and gels. These are applied directly to the teeth with a brush or a thin strip, usually once or twice a day for 10 to 14 days. Results are usually subtle, and may cost from $10 to $55.
- Tray-based systems. With this option, a mouth guard-like tray is filled with a bleaching gel or paste and placed over the teeth for one to several hours a day for up to four weeks. You can buy tray-based tooth whitening systems over-the-counter or have one custom-fitted by your dentist and the cost ranges from $150 to $600.
- Whitening toothpastes. Because they’re mildly abrasive, every toothpaste helps remove stains from teeth. Whitening toothpastes, however, also contain chemicals or polishing agents that help scrub stains from teeth. Whitening toothpastes are inexpensive and usually brighten teeth by about one shade. Remember when selecting a whitener or any dental product, be sure to look for the ADA Seal of Acceptance.