Should You Floss Before or After Brushing Your Teeth?

Getty Images

It's an argument that's raged on for years: Should you floss before or after brushing your teeth? Some people are firmly in the floss-first camp, while others swear brushing should be the first thing you do — and plenty will die on that hill.

"There has been a lot of debate about this," says Uchenna Akosa, D.D.S., director of Rutgers Health University Dental Associates. But, for all of the chatter on the topic, it turns out that there's actually no right or wrong answer here.

Even the American Dental Association says whether to floss or brush first is up to you, noting that, "either way is acceptable as long as you do a thorough job." What the ADA does recommend, though, is that you brush twice a day and clean between your teeth with floss or another interdental cleaner (e.g. a soft toothpick) at least once a day. "The bottom line is that the best time to floss is the time that fits well with the individual's schedule," according to the ADA.

Reminder: Flossing is important because it helps remove debris and plaque that builds up between your teeth, lowering your risk of gum disease (aka gingivitis) and tooth decay, points out Mark Wolff, D.D.S., Ph.D., dean of the University of Pennsylvania School of Dental Medicine. Plaque is a sticky white film that contains bacteria, which produces acids that can destroy tooth enamel (the hard, protective, outermost layer of teeth), cause cavities, and lead to gum disease, according to the Cleveland Clinic. Eventually, plaque can harden and turn into tartar, which requires a professional oral cleaning to eliminate (read: brushing and flossing are no longer effective). What's more, it can also ultimately cause periodontal disease — a serious infection that damages the gums and can destroy the bone that supports your teeth, according to the Mayo Clinic. Oof. (See also: Why You Should Remineralize Your Teeth — and Exactly How to Do It, According to Dentists)

Ok, so dentists agree that what really matters is that you actually floss on a regular basis (instead of, you know, just telling your dentist that you do it) and not when you do it — but that's not all there is to this debate.

The Case for Flossing First

Here's the thing: Flossing before brushing can actually leave you with a cleaner-feeling mouth afterward if nothing else, according to Akosa. Why? Brushing after you floss gives you the chance to brush away the gunk you pull out from between your teeth vs. just letting some of the residues hang out in your mouth. (Related: What Is a Deep Teeth Cleaning Dental Procedure?)

Think of it this way: Your toothbrush does a pretty solid job of getting food and plaque off the surface of your teeth, and even at dislodging some of the stuff that's between them, says Wolff. But floss allows you to really get in between your chompers to confidently nix any potentially harmful gunk hiding in there as well, according to the ADA.

And while there hasn't been a ton of research on the best brushing and flossing order, Akosa points to a small study of 25 dental students published in the Journal of Periodontology in 2018 that found flossing first is better. The study randomly assigned people to brush before flossing, while others had to floss before brushing, and researchers measured their levels of plaque and fluoride before and after. The researchers discovered that the flossing-before-brushing group had a significant reduction in plaque between the teeth and overall plaque levels compared to the brushing-flossing group. Levels of fluoride — a mineral that helps prevent tooth decay — were also higher in the flossing-brushing group. This study was small and it's hard to draw a lot of conclusions from it, but it's something.

TL;DR — You can technically floss or brush first, as long as you're flossing at least once a day and brushing at least twice. (Ok, but should you brush your teeth before or after breakfast?)

The Optimal Dental Hygiene Routine

All that being said, if you're looking to really achieve the cleanest mouth possible, Akosa and Wolff recommend following these steps for an A+ oral hygiene routine:

Step 1: Floss

By now you (hopefully!) realize that experts recommend flossing at least once a day — something you can accomplish using a variety of tools. As for which one is best? It's pretty much up to you (think: what you find most comfortable, effective, etc), as long as you're not reaching for hard wooden toothpicks since these "can damage the sides of the tooth," says Wolff.

Soft toothpicks and interdental brushes, on the other hand, are specially designed to help get out any larger gunk that might be hanging around your teeth. You can use these instead of traditional string floss for your once-daily flossing since they basically both do the same thing, says Wolff. But if you really want to make sure you get everything out, Wolff suggests using string floss (or even floss picks) and then going back through with the interdental brushes. These toothpick-like tools are also a good option if you're interested in flossing during the day, say, after lunch while you're still at the office. Just take it from Wolff: "I typically clean between my teeth with a soft toothpick or interdental brush while sitting in my car," he says. These little devices are "really very effective at cleaning debris in your teeth." There are a lot of options out there, but GUM Proxabrush Go-Betweens Interdental Brushes (Buy It, $7 for 10, amazon.com) and Up & Up Simple Interdental Brushes (Buy It, $3, target.com) can both be handy.

And then there's good old string floss, which often comes as waxed or unwaxed. The ADA says there's no difference in the effectiveness between the two types, although waxed might slide easier between your teeth. So whether you use Reach Waxed Dental Floss (Buy It, $13 for five, amazon.com) or GUM Butler Weave Unwaxed Floss (Buy It, $11 for two, amazon.com), be sure to wrap about 18 inches of it around the middle finger with the rest wound around the opposite middle finger, according to the ADA. Then, hold a small amount of floss — about 1 inch — tightly between your thumb and forefingers and gently insert it between the teeth. Rub up and down, pressing against each tooth as you move throughout the whole mouth. (Related: This Floss Turned Dental Hygiene Into My Favorite Form of Self-Care)

Step 2: Brush

After you've picked and flossed your teeth, move on to brushing. Doing so for at least two minutes helps remove plaque and debris that was once lurking between your teeth, says Wolff. And, if you use a toothpaste that contains fluoride, it can further help lower your risk of cavities, he adds.

The ADA specifically recommends you place your toothbrush at a 45-degree angle to your gums, gently move the brush back and forth in short, tooth-wide strokes, and make sure to brush the outer surfaces, the inner surfaces, and the chewing surfaces of your teeth. To get the inside surfaces of your front teeth, tilt your brush vertically and make several up and down strokes. Overall, you should brush for two minutes, twice a day, according to the ADA. As for how much toothpaste to use, Wolff suggests using a pea-sized amount: "You do not need to cover the whole brush."

Contrary to what some people say, both electric toothbrushes — e.g. Colgate hum Smart Electric Rechargeable Sonic Toothbrush (Buy It, $41, amazon.com) — and manual toothbrushes — e.g. Colgate 360 Advanced Optic White Toothbrush (Buy It, $7 for two, amazon.com) — can clean your teeth sufficiently; the ADA has no preference. That said, there is some research to suggest that electric toothbrushes may be more effective at keeping your teeth clean over time. One longitudinal study looked at the teeth and gums of 2,819 participants, some of whom used electric toothbrushes while others used manual. The researchers found that, after 11 years, folks in the electric toothbrush group had less gum disease and less tooth loss than the manual toothbrush group.

Step 3: Use Mouthwash

It's important to use mouthwash as the final step in your oral hygiene routine because "if you use it before you brush, you'll get rid of all of the ingredients when you brush and it will lose its effectiveness," says Akosa. What do mouthwashes do exactly? "If you swish after brushing, [they] can continue to decrease the amount of plaque on your teeth, provide fluoride, and reduce gingivitis," explains Wolff. (Related: Can Mouthwash Kill the Coronavirus?)

As for what type of mouthwash to use really depends on your personal preferences. For example, some people might prefer mouthwashes that whiten — e.g. Crest Pro-Health Advanced Extra Whitening Mouthwash (Buy It, $7, amazon.com) — while others might like those designed for sensitive teeth — Sensodyne Pronamel Mouthwash (Buy It, $19, amazon.com). But neither of these features are a requirement for a good mouthwash, notes Wolf, who is a fan of those that contain fluoride. "They help reduce tooth decay," he explains. "I want to be able to use it and leave the residual from the wash sitting on the teeth." Aim for swishing the liquid around in your mouth for at least one minute, suggests Wolff. You may need to work up to that, since you may be sensitive to the stinging that mouthwashes (especially those with alcohol) can cause in the mouth.