Baking soda is one of the gentlest abrasives you can put on your teeth, with a Relative Dentin Abrasivity (RDA) score of just 7, compared to 45 to 84 for most commercial whitening toothpastes. That makes it a surprisingly effective and low-risk option for removing surface stains and freshening your mouth. Here’s how to use it properly and what it can (and can’t) do.
How to Make and Apply a Baking Soda Paste
Mix equal parts baking soda and water in a small bowl until you get a smooth, spreadable paste. A teaspoon of each is plenty for one session. The consistency should be thick enough to stay on your toothbrush without dripping off.
Dip a soft-bristled toothbrush into the paste and brush in gentle circles, covering each tooth thoroughly. Don’t press hard. The goal is to let the mild abrasive particles do the work, not force from your hand. Brush for about one minute, then spit and rinse your mouth well with water. Some people find the salty, slightly gritty taste unpleasant at first, but it fades quickly.
You can also dip a wet toothbrush directly into dry baking soda if you prefer. The paste method just gives you more control over the texture and makes it easier to spread evenly.
Why It Works on Stains
Baking soda whitens teeth differently than peroxide-based whitening strips or gels. Those products bleach stains chemically by penetrating the enamel. Baking soda works mechanically, physically scrubbing away the thin stained film that builds up on the outer surface of your teeth from coffee, tea, wine, and other pigmented foods.
What’s interesting is that researchers have found baking soda removes stains more effectively than its low abrasivity score would predict. A review in the Journal of the American Dental Association noted that because baking soda is less abrasive than the silica used in most commercial toothpastes, its whitening ability likely involves additional mechanisms beyond simple scrubbing. It also has natural acid-buffering properties, meaning it helps neutralize the acids that oral bacteria produce. Those acids are what erode enamel and create the rough, porous surface where stains take hold more easily.
How Abrasive Is It, Really?
This is where baking soda has a genuine advantage. The RDA scale measures how much a substance wears down tooth structure, with anything under 250 considered safe by the ADA. Plain baking soda scores a 7. To put that in perspective:
- Plain baking soda: RDA of 7
- Arm & Hammer Advance White: RDA of 30
- Colgate Whitening: RDA of 53
- Crest Pro Health Whitening: RDA of 78
- Colgate 2-in-1 Tartar Control/Whitening: RDA of 84
That means plain baking soda is roughly 4 to 12 times less abrasive than popular whitening toothpastes. Research published in JADA confirmed that baking soda dentifrices are safe for daily use, do not contribute to root sensitivity, and are low enough in abrasiveness to be suitable for long-term oral hygiene routines. If you’ve been told you have thin enamel or receding gums, baking soda is actually one of the safer cleaning options available.
How Often You Can Use It
Despite what you may have read about limiting baking soda to a few times per week, dental research supports daily use. The JADA review specifically describes baking soda’s low abrasivity as making it “especially suited for safe daily use in oral hygiene regimens.” The concern about overuse likely stems from confusion between baking soda and harsher DIY whitening methods like lemon juice or activated charcoal, which genuinely can damage enamel.
That said, if you’re using plain baking soda rather than a commercial toothpaste that contains it, you’re missing out on fluoride. Fluoride is what strengthens enamel and prevents cavities, and baking soda alone doesn’t provide it. A practical approach is to brush with baking soda paste once a day for stain removal and use a fluoride toothpaste for your other brushing session. This way you get the whitening benefit without sacrificing cavity protection.
What Baking Soda Won’t Do
Baking soda removes surface stains, but it won’t change the underlying color of your teeth. If your teeth are naturally more yellow or have become discolored from medications, aging, or damage to the inner layers, baking soda won’t make a visible difference. That kind of discoloration requires peroxide-based bleaching, either from whitening strips or professional treatments.
It also won’t prevent cavities on its own. While its acid-neutralizing properties create a less hospitable environment for the bacteria that cause tooth decay, it lacks fluoride and antimicrobial ingredients found in standard toothpastes. Think of it as a complement to your regular oral care, not a replacement.
Common Mistakes to Avoid
The biggest mistake people make is brushing too aggressively. Baking soda’s gentleness only holds up if you use light pressure. Scrubbing hard with any abrasive, even a mild one, can irritate gum tissue over time. Use the same soft, circular motions you’d use with regular toothpaste.
Another common error is mixing baking soda with lemon juice, apple cider vinegar, or hydrogen peroxide in an attempt to boost whitening. Acidic ingredients like lemon juice and vinegar soften enamel, and brushing softened enamel actually strips it away. If you want to combine baking soda with something, stick with plain water. Some people add a drop of peppermint oil for flavor, which is fine, but acids are counterproductive.
Finally, don’t expect dramatic overnight results. Surface stains lighten gradually over days to weeks of consistent use. If you’re comparing the experience to whitening strips, which deliver noticeable results in a few days through chemical bleaching, baking soda works on a slower timeline because it’s removing stain mechanically rather than altering tooth chemistry.