Achieving white teeth can be tricky. Sure, you can use all the straws in the world to avoid coffee strains and brush your teeth twice a day, but your teeth may still not be the white hue you want. And while there are so many teeth whitening methods out there, one that you should consider is using a teeth whitening pen.

"Whitening pens are very affordable, even compared to OTC whitening strips, and in-office products and procedures," says Dr. Marina Gonchar, DMD, founder of Skin to Smile. "They are extremely simple to use and do not require more than one to two minutes to apply on all the teeth."

Another bonus: Whitening pens allow for more controlled application. "They are very precise, and the whitening solution will only be applied to your teeth, avoiding your gums and any other areas of your mouth," adds Dr. Gonchar. "Whitening pens can be used on individual teeth as opposed to whitening strips that will be applied to your entire mouth."

And if you have sensitive teeth, or teeth whitening tends to make your teeth even more sensitive, teeth whitening pens are a great option. "The concentration of the whitening solution is significantly less compared to other OTC products and in-office products which will result in less tooth sensitivity post-whitening," says Dr. Gonchar.

Not to mention you can use them anywhere. "The main benefit of teeth whitening pens is the convenience," says Dr. Brian Harris, DDS/DMD, lead medical advisor at SNOW® and Frost Oral Care. "Because it is portable and able to fit in your pocket or purse, you can take it with you wherever you go."

But one thing to keep in mind: They're not necessarily the most effective method to whiten your teeth. "They are about as effective as using a whitening mouth rinse," says Dr. Rhonda Kalasho, DDS, CEO of TruGlo Modern Dental.

If you really want the most effective treatment, she suggests laser teeth whitening. "Not only does laser teeth whitening produce fast results, but it is also the safest treatment plan," she says.

But when shopping for an effective teeth whitening pen, you should look for a few common ingredients including hydrogen peroxide and carbamide peroxide. "You want to make sure the product you purchase has at least one of these whitening ingredients or a combination of the two," says Dr. Gonchar.

She adds that other ingredients to look out for are potassium nitrate, which is a powerful desensitizer, and sodium fluoride, which also has desensitizing properties and prevents the formation of cavities. "Some ingredients to try to avoid in whitening pens is polyethylene glycol, which is touted as a cleansing agent, and diethanolamine," she adds.

And yes, you can use teeth whitening pens daily. Dr. Daniel Rubinshtein, DDS, cosmetic dentist in New York City, notes that teeth whitening pens should be used once a day, for five to seven days to see some type of results.

If you don't notice any sensitivity, you can even use them more than once a day. "The important thing is to minimize the amount that you ingest and to stop using if you notice any negative side effects to the teeth or gums," Dr. Snow says. "Using a whitening pen two to three times a day is okay as long as the gel is not as strong as traditional whitening agents."

In the market for a new teeth whitening pen? Here are 10 of the best teeth whitening pens to try.