What is the Best Alkaline Mouthwash?

Updated September 2026

A patient told us the only soda she drinks is diet and felt her teeth should still be protected since this soda is sugar free. So why is she still getting cavities and what does soda have anything to do with mouthwash? Glad you asked.

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The Science

The bacteria in your mouth cannot start creating cavities UNLESS it is bathed in an acidic environment below 5.5pH.

It does not matter if the food or drink you put in your mouth has "zero sugar," you still can get cavities if your mouth is bathed long enough in acids. On average it takes your mouth about one hour to return from an acidic to neutral environment. Most things we eat or drink cause our mouth to become acidic so the sooner our mouth can return to a more neutral pH after eating, drinking, or using mouthwash helps prevent cavities. This is why alkaline products are important. On the pH scale from 0-14, the higher the number, the safer your mouth is from creating cavities.

Most drinks (soda, juices, sports drinks, energy drinks, coffees, teas), flavored bottled water, and most mouthwashes are acidic.

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Mouthwash and Acidity

We suggest everyone use mouthwash because they have beneficial advantages. Mouthwash reaches areas that floss and toothpaste do not. Particular mouthwashes aid in treating gingivitis, bad breath, cavity formation and prevention. Though mouthwash should never replace brushing and flossing, it is an excellent adjunct in caring for your teeth.

However, most mouthwashes on the market are acidic. This means that though some effectively kill off bacteria that cause cavities, their acidity creates an environment for the same bacteria to grow back even faster and almost nullifies what you are trying to accomplish.

What is an alkaline mouthwash? Simply put, a true alkaline mouthwash has greater than a 7.0 pH. However, for everyday cavity prevention, an alkaline mouthwash does not strictly need to be alkaline. It just needs to be enamel-safe meaning the pH is above the 5.5 pH cavity-causing danger zone. We tested nearly all mouthwashes on the market. See the table below if your brand is alkaline or acidic.

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Mouthwashes to AVOID that are Acidic Enough to Cause Cavities

The pH of the following mouthwashes are in the acidic range under the 5.5pH. Surprisingly most of these are popular mouthwashes from Listerine, Colgate, Scope, and even the natural mouthwash like Toms of Maine or Natural Dentist. If you're going on a trip or something short these are fine, but if this is part of your regular daily routine then consider a different mouthwash.

Comparing Sodas to Common Mouthwash pH Levels

**Colgate Optic White, Colgate Peroxyl, Colgate Total Enamel Health, Colgate Total Gum Health, Crest 3D Whitening, Crest Pro-Health, Equate Antiseptic Mouthwash, Equate Tartar Control+, Listerine Cool Mint Antiseptic, Listerine Smart, Listerine Total Care, Listerine Zero, the Natural Dentist Anti-Gingivitis Rinse, PerioBrite, Scope Outlast, Smartmouth, Sonicare BreathRx, Toms of Maine (Wicked Fresh)

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Good Mouthwashes

These not only do what they advertise but also create an environment that prevent cavities. Pick one of these to use and feel confident that you are protecting your teeth. These come recommended and are not necessarily inferior to the Top 3 Alkaline Mouthwashes.

**All ACTs (Dry Mouth, Bubble Gum, Restoring, Wild Watermelon, Zero Alcohol), Biotene, Equate Anticavity Fluoride Mouthwash, Hello Activated Charcoal, and Peridex (prescription).

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The Top 3 Alkaline Mouthwashes

Three mouthwashes ranked the highest based on alkaline pH:

• Plax is ideal pre brushing to loosen plaque

• Therabreath is ideal for bad breath

• PRO Maintenance Rinse is ideal for cavity prevention

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Conclusion

This study only focuses on acidic levels of mouthwashes and does not discuss the benefits of particular ingredients. Those benefits are trumped by how acidic a mouthwash is though. Know that nearly all mouthwashes have their benefits if used in short-term spurts. However, if your goal is to do all you can to not get cavities, we suggest using a mouthwash that does not foster cavity-causing bacteria to quickly grow after mouthwash use. Any of the outlined "good" mouthwashes fill that role though the best three alkaline mouthwashes in this case are Plax, Therabreath, or PRO Maintenance Rinse.

Red acidic range where cavity-causing bacteria thrive

Green above that acidic range

Blue therapeutic mouthwash

	Mouthwashes in Alphabetical Order
pH	Mouthwash
6.36	ACT Dry Mouth
6.94	ACT Bubble Gum
6.37	ACT Cinnamon (Zero Alcohol)
6.51	ACT Restoring Cool Mint
6.91	ACT Wild Watermelon
6.63	Biotene
4.92	Colgate Optic White Mouthwash
4.17	Colgate Peroxyl
3.50	Colgate Total Enamel Health
4.57	Colgate Total Gum Health
5.04	Crest 3D White Brilliance
3.43	Crest 3D White Diamond
5.55	Crest 3D White Glamorous Multicare Whitening
4.98	Crest 3D White Multi-Care Whitening Rinse
4.65	Crest Pro Health Clean Mint
3.33	Crest Pro-Health Advanced Extra Whitening Alcohol Free
9.00	PRO Maintenance Rinse (Previously called CTx3)
4.49	Equate Antiseptic Mouthrinse
7.12	Equate Restoring Anticavity Fluoride
3.69	Equate Tartar Control Plus
4.67	GotFreshBreath
7.52	Hello Activated Charcoal
3.89	Listerine Cool Mint Antiseptic
3.07	Listerine Total Care
4.29	Listerine Zero
3.02	Natural Dentist Anti-Gingivitis Rinse
5.61	Peridex
5.0	PerioBrite
8.01	Plax
5.21	Scope Outlast
5.00	Smartmouth Clinical DDS
5.25	Smartmouth Dry Mouth
5.43	Smartmouth (Original)
4.10	Sonicare BreathRx
9.82	Therabreath
4.13	Toms of Maine (Wicked Fresh)