Is Baking Soda Teeth Whitening Safe? What the Abrasion Data Actually Show

The abrasion myth: what most sources get wrong about baking soda teeth whitening

Search for advice on baking soda teeth whitening and you’ll encounter the same warning repeated across dozens of sites: it’s too abrasive for regular use, it will wear away your enamel, use it sparingly if at all. The claim is so pervasive that it’s treated as settled fact. The measured abrasion data tell the opposite story.

Baking soda (sodium bicarbonate) has a Relative Dentin Abrasivity (RDA) of approximately 7 on the ISO standardized scale.⁷ To put that number in context, the FDA’s upper safety limit for toothpaste abrasivity is an RDA of 200, and most commercial whitening toothpastes measure between 100 and 200.⁷ Regular fluoride toothpastes typically fall in the 40 to 70 range.⁸ Baking soda sits well below all of them.

The contradiction between reputation and measurement is stark. When we say “baking soda is too abrasive,” we’re comparing it not to the evidence but to an unexamined assumption. The abrasion concern isn’t baseless, abrasive particles in any dentifrice can remove enamel if the RDA is high enough or if applied with excessive force. But baking soda itself ranks among the least abrasive substances used in oral care.¹

This matters because the choice to avoid baking soda toothpaste or to limit it to occasional use is often based on misinformation. If the goal is to minimize enamel wear while removing surface stains, the RDA data point in the opposite direction from the conventional wisdom. What follows is what the clinical literature actually shows about baking soda and teeth whitening: how it works, what it removes, what it doesn’t, and the trade-offs that do matter.

What the RDA data show about baking soda and teeth whitening

The Relative Dentin Abrasivity (RDA) scale is the ISO-standardized method for measuring how much a toothpaste abrades tooth structure under controlled brushing conditions. Higher RDA means more material removal. An RDA below 70 is considered low abrasivity; 70 to 100 is medium; 100 to 150 is high; and above 150 is very high.⁸ The FDA caps over-the-counter toothpastes at RDA 200.

A 2022 study measuring the RDA and polishing effect of eleven commercial whitening toothpastes found that baking soda had an RDA of approximately 7, the lowest value tested.⁷ For comparison, the whitening products in that study ranged from RDA 103 to RDA 190. Even non-whitening fluoride toothpastes commonly exceed RDA 40.⁸

Relative Dentin Abrasivity (RDA) values for baking soda compared to commercial toothpastes

The practical implication is that brushing your teeth with baking soda produces less enamel wear per brushing cycle than nearly any commercial alternative. A 2023 laboratory study confirmed that toothpastes with lower RDA values caused significantly less enamel and dentin wear over simulated brushing cycles.⁸ A 2022 systematic review and meta-analysis of whitening toothpaste effects on enamel found that while some formulations increased surface roughness, the RDA value was the strongest predictor of wear.⁹

This does not mean baking soda is risk-free. Abrasion is cumulative, and technique matters. Brushing with excessive force or frequency can damage enamel regardless of RDA. But the notion that baking soda is uniquely harsh contradicts the measurement data. If anything, choosing baking soda over a high-RDA whitening paste reduces abrasion risk.

How baking soda removes surface stains

Baking soda whitens teeth through two mechanisms: mechanical abrasion and chemical disruption of the protein pellicle that binds stains to enamel.¹ Both matter, and both are gentle relative to alternatives.

The mechanical component comes from the physical shape and hardness of sodium bicarbonate crystals. When suspended in water or saliva and brushed against enamel, these particles dislodge surface debris and stain molecules. Because the crystals are soft (Mohs hardness around 2.5, compared to enamel’s 5), they polish without gouging.¹ The low RDA reflects this softness.

The chemical component is less well known but equally important. Baking soda is mildly alkaline, with a pH around 8.3 when dissolved. This alkalinity disrupts the acquired pellicle, the thin protein film that forms on teeth and provides a binding surface for chromogenic (stain-causing) compounds from coffee, tea, tobacco, and food.² By weakening the pellicle’s structure, baking soda makes it easier for mechanical brushing to lift stains that would otherwise cling tenaciously to the enamel surface.

A 2017 review summarizing the clinical literature on baking soda dentifrices concluded that this dual-action mechanism (mechanical plus chemical) explained why formulations containing baking soda consistently outperformed control toothpastes in stain removal trials, even when the abrasivity was held constant.² It’s not just scrubbing; it’s also dissolving the glue that holds stains in place.

The result is effective extrinsic stain removal with minimal enamel wear. A 2012 randomized controlled trial comparing a baking soda and peroxide dentifrice to a standard fluoride control found significantly greater stain reduction in the baking soda group at two, four, and six weeks, with no adverse effects on enamel reported.³ A 2017 trial testing sodium bicarbonate combined with hydrogen peroxide and a remineralizing agent (CPP-ACPF) found similar whitening efficacy and no reduction in enamel microhardness.⁴

These studies confirm that when baking soda is used as intended (brushing twice daily with normal force), the whitening effect comes from surface cleaning, not enamel erosion.

The surface-stains-only limitation

The honesty that the evidence demands: baking soda removes extrinsic (surface) stains effectively, but it does not alter intrinsic tooth color. If your teeth are stained from coffee, tea, red wine, or smoking, baking soda can restore them closer to their natural shade. If your teeth are naturally dark, yellowed from aging, or discolored from tetracycline or fluorosis, baking soda will do nothing.²

This distinction between extrinsic and intrinsic discoloration is critical and often glossed over in product marketing. Extrinsic stains sit on the enamel surface or within the pellicle; they’re removable by abrasion or chemical disruption. Intrinsic stains originate within the dentin or enamel structure itself; they require chemical bleaching agents (typically hydrogen peroxide or carbamide peroxide) to oxidize the chromophores and lighten the underlying tooth color.¹¹

A 2018 Cochrane review of home-based chemical whitening found that peroxide-based bleaching gels produced measurable color change on standardized shade guides, typically two to three shades lighter.¹¹ Baking soda does not produce that type of change. A 2018 systematic review of whitening dentifrices confirmed that while these products reduce extrinsic discoloration, their effect on intrinsic color is negligible.¹⁰

The implication: if your goal is to remove surface buildup and restore your teeth’s baseline appearance, baking soda works. If your goal is to make your teeth whiter than their natural shade, you need a bleaching agent. Baking soda is not a substitute for peroxide-based whitening systems, and no amount of brushing with it will replicate the results of in-office or at-home chemical bleaching.

This limitation isn’t a flaw; it’s a category difference. But it’s one that should be stated plainly so expectations align with the chemistry.

Commercial baking soda toothpaste vs. DIY

You can brush with plain baking soda mixed with water, or you can use a commercial toothpaste formulated with baking soda as an active ingredient. The question is whether the formulation matters.

The evidence suggests it does. A 2015 in vitro study compared DIY baking soda paste (sodium bicarbonate mixed with water) to commercial whitening products and found that the DIY preparation was less effective at stain removal than formulated baking soda dentifrices.⁵ The likely reason is particle size and dispersion. Commercial formulations control the size and distribution of sodium bicarbonate crystals to optimize contact with the tooth surface; a home mixture does not.

Additionally, commercial baking soda toothpastes often combine sodium bicarbonate with other active ingredients. The trials showing the strongest whitening effects tested baking soda plus hydrogen peroxide, not baking soda alone.³⁴ Peroxide adds a mild bleaching component that extends efficacy beyond surface stain removal. Some formulations also include remineralizing agents (such as calcium phosphate compounds) to counteract any demineralization risk, though at baking soda’s low RDA that risk is minimal.⁴

The DIY approach has one advantage: cost. A box of baking soda costs less than any tube of toothpaste. But the trade-off is reduced efficacy, no fluoride (covered in the next section), and the inconvenience of mixing your own paste. If you’re choosing baking soda for its low abrasivity and stain-removal ability, a formulated product delivers both more reliably.

For context, commercial whitening products that include baking soda in their formulation combine the low-abrasion benefit with active whitening agents and fluoride. If you’re looking for a formulated whitening product that balances efficacy with enamel safety, options like Purely White Deluxe or LaughLand represent the types of products we evaluate in our whitening product guides, though we did not test them in-house for this review.

The fluoride trade-off you shouldn’t ignore

Plain baking soda contains no fluoride. That’s the single most important limitation for daily use, and it’s one that gets buried beneath the abrasion debate.

Fluoride is the most effective and widely validated intervention for preventing dental caries (cavities). A 2024 Cochrane review analyzing decades of water fluoridation data found that fluoride reduces cavities in children and adults, with the benefit proportional to exposure.¹² Toothpaste is one of the primary fluoride delivery mechanisms in non-fluoridated areas, and skipping it has consequences.

If you brush exclusively with plain baking soda or a baking soda paste that contains no fluoride, you lose that protection. A 2011 in vitro study examining enamel lesions from whitening dentifrices noted that fluoride-free formulations posed a demineralization risk, particularly when combined with acidic dietary exposures.⁶ The study didn’t single out baking soda, but the principle applies: no fluoride means no remineralization support.

The solution is straightforward. Use a baking soda toothpaste that includes fluoride, or supplement with a fluoride mouth rinse if you prefer DIY baking soda brushing. Most commercial baking soda dentifrices now include sodium fluoride at concentrations comparable to standard toothpaste (typically 1,000 to 1,450 ppm). Check the label.

This isn’t a minor detail. The abrasion concern is overblown; the fluoride concern is not. If you’re switching to baking soda for its low RDA and effective stain removal, make sure you’re not inadvertently increasing your cavity risk by eliminating fluoride.

Sources

All clinical claims in this review are backed by peer-reviewed published research. The sources list includes randomized controlled trials, systematic reviews, meta-analyses, and laboratory studies measuring RDA and enamel effects. We did not test baking soda preparations in-house; the conclusions synthesize the published evidence.