These Are the Best Teeth Whitening Kits to Keep Your Smile Nice and Bright, According to Experts

Even if you brush your teeth twice daily as recommended by your dentist and follow up with cleanings in between your meals, there's still a chance that your pearly white smile can lose its luster. Grabbing too many iced coffees before class and late-night snacking on your favorite chocolate bars can make your teeth less white. It's no cause for alarm, though. You can try out a teeth whitening kit whenever you notice your smile becoming a little dull.

Before heading out to find the best teeth whitening kit, it's important to understand how teeth stains and discoloration occur. Pigmented residue from foods, drinks, and things like smoking are "absorbed by the surfaces of the teeth, creating a discoloration," Dr. Kami Hoss, D.D.S, tells Seventeen. In other instances, stain molecules team up with a sticky substance called biofilm in the mouth and when it's not thoroughly cleaned off through brushing and flossing, "the biofilm and stain molecules discolor the teeth." Dr. Jonathan B. Levine, DMD, JBL New York City CEO, adds. It's not just what you chew on that impacts discoloration. Author of If Your Mouth Could Talk, Dr. Hoss also contributes "aging, trauma, certain medications, and dental restorations" to a less bright smile. Understanding why your smile begins to fade can help you decide which whitening method you should choose.

How do teeth whitening kits work?

Hydrogen peroxide is one of the most common ingredients found in whitening kits. It works alongside carbamide peroxide to "partially penetrate the layers of the teeth, removing compounds that cause discoloration" with the help of diluted baking soda, which also helps remove stains, Dr. Hoss explains. It's all about concentration. Dr. Levine says, "the higher the concentration of the gel and the amount of time it is on the teeth, the better the results." He suggests a maximum of 9% to 10% hydrogen peroxide for a short wear time and 27% carbamide peroxide for at-home whitening. Both peroxides work together to generate whitening oxygens, creating ammonia as a byproduct. The gums can dry out and develop sensitivity when exposed to too much ammonia. So it's important to be mindful of concentration and how long you leave it on your teeth. Each whitening kit works differently. If you're using a whitening kit that comes equipped with trays and gels, Dr. Levine advises against using them for longer than 30 minutes.

How fast can you see results?

While you may want to whiten your teeth overnight, it can take days and sometimes a few weeks before you notice a true change. Teeth whitening done by a dentist can get teeth up to five shades whiter "in under an hour," Dr. Levine, GLO Science founder says, but at-home teeth whitening kits take anywhere from "five to seven days to get the five shades" brighter when using up to an eight-minute whitening kit daily.

If you're in a time crunch and need fast results, Dr. Kami Hoss suggests toothpaste enriched with at least 10% nano-hydroxyapatite. Along with being naturally present in teeth, hydroxyapatite "is a calcium mineral that helps restore luster damaged by bleaching agents and naturally whitens teeth."

This may be a well-kept secret, but the foods you eat can also help whiten your teeth. According to Dr. Levine, fruits and vegetables like apples, carrots, and asparagus have an "alkalizing effect on the mouth, and the higher pH creates a better environment for gum health and less decay." These foods also act as exfoliators that remove stains from the teeth as you chew.

Can teeth whitening kits replace dental cleanings and checkups?

While teeth whitening kits can transform your smile when it gets a little dull, both dentists advise that teeth whitening kits cannot replace or substitute routine dental cleanings. "Dental checkups and cleanings are critical for your oral health to get to problems before they become big problems," Dr. Levine warns. Instead of frequent at-home whitening, Dr. Hoss recommends routine cleanings where dentists remove "plaque and stains with professional tools" at least twice a year to preserve oral health and provide a long-term solution.

What are the side effects of teeth whitening kits?

Tooth sensitivity is one of the most common side effects of teeth whitening kits, but other long-term issues may arise. The strength of bleaching concentration found in whitening kits and the duration of use can contribute to potential dental damage. According to Dr. Hoss, excessive teeth whitening can lead to "inflammation of the dental and gingival tissues, which can lead to secondary issues, such as infections." Overbleaching also dulls the teeth and removes their luster over time. Dr. Hoss recommends whitening your teeth with at-home kits between once and twice a year due to "potential risks and long-term damage to teeth."

Having a bright white smile is important, and if your pearly whites begin to fade, there are so many different teeth whitening kits to help. Read ahead for the best dentist-recommended teeth whitening kits to keep your smile stays bright.