The short answer: floss first, brush second, and save mouthwash for a completely different time of day. This sequence gives you the best shot at removing plaque between your teeth and letting fluoride from toothpaste do its job. That said, the order matters less than most people think, and doing all three consistently matters far more than perfecting your sequence.
Why Flossing First Makes Sense
A 2018 clinical trial published in the Journal of Periodontology found that people who flossed before brushing had significantly higher fluoride concentrations in the plaque between their teeth compared to those who brushed first. The logic is straightforward: flossing clears out the debris and bacterial buildup packed between teeth, so when you brush afterward, the fluoride in your toothpaste can actually reach those freshly cleaned surfaces.
That said, a 2021 systematic review and meta-analysis looked across multiple studies and found no statistically significant difference in overall plaque removal between the two sequences. So while flossing first appears to improve fluoride delivery between teeth specifically, total plaque scores come out roughly the same either way. The American Dental Association takes a neutral stance, saying either order is acceptable as long as you’re thorough.
If you’re going to pick one approach and stick with it, flossing first has a slight edge. But if you’ve been brushing first for years and your dental checkups are clean, there’s no urgent reason to switch.
Brushing Comes Second
After flossing, brushing serves two purposes: it physically scrubs plaque off the broader surfaces of your teeth, and it deposits a layer of fluoride across your enamel. That fluoride coating is more valuable than most people realize. It strengthens enamel and makes it more resistant to the acids that cause cavities.
Here’s where a common mistake comes in. Most people rinse their mouth with water immediately after brushing. This washes away the concentrated fluoride left behind by your toothpaste, reducing its protective effect. Instead, spit out the excess foam but skip the water rinse. It feels a little odd at first, but the fluoride needs time on your teeth to work. The ADA notes that leaving fluoride on your enamel for at least 15 minutes after brushing makes it meaningfully more resistant to acid damage.
Mouthwash Belongs at a Different Time
This is the part that surprises most people. Using mouthwash right after brushing, even a fluoride mouthwash, actually undermines your toothpaste. Research on salivary fluoride levels found that rinsing with a non-fluoride mouthwash immediately after brushing significantly reduced the amount of fluoride retained in the mouth compared to not rinsing at all. Even fluoride mouthwashes contain a lower concentration of fluoride than toothpaste, so swishing one right after brushing dilutes the stronger fluoride you just applied.
The UK’s National Health Service is especially direct about this: “Don’t use mouthwash (even a fluoride one) straight after brushing your teeth because it will wash away the concentrated fluoride in the toothpaste left on your teeth.” Their recommendation is to use mouthwash at a completely separate time, such as after lunch.
This makes mouthwash most useful as a midday boost. After a meal, when you likely haven’t brushed, a fluoride mouthwash freshens your breath and adds a layer of fluoride protection during a gap in your routine. Used this way, it complements brushing rather than competing with it.
The Ideal Daily Routine
Putting it all together, a practical schedule looks like this:
- Morning or night (or both): Floss between all teeth, then brush for two minutes with fluoride toothpaste. Spit but don’t rinse with water.
- After lunch or another meal: Use a fluoride mouthwash, swishing for 30 seconds. Don’t eat or drink for 30 minutes afterward to let it absorb.
You only need to floss once a day. Most dentists suggest doing it at night so food particles don’t sit between your teeth while you sleep, but morning works too. Brushing should happen twice a day.
If You Can’t Separate Mouthwash From Brushing
Realistically, not everyone is going to carry mouthwash to the office. If you want to use it as part of your brushing session, the best compromise is to wait at least 15 minutes after brushing before rinsing. This gives the fluoride from your toothpaste enough contact time to absorb into your enamel before you dilute it.
Another option is to use mouthwash before you floss and brush. Some products are specifically marketed as “pre-brushing rinses” designed to loosen plaque before you clean mechanically. The evidence on whether these meaningfully improve plaque removal is mixed, but at the very least, using mouthwash first avoids the problem of washing away your toothpaste’s fluoride.
The worst option, from a fluoride standpoint, is the one most people default to: brush, rinse with water, then immediately swish with mouthwash. This sequence strips away the most protective layer your routine produces.