Is Sparkling Water Actually Gentler on Your Teeth Than Soda?
Clinically reviewed by Dr. Abinaash Kaur, DDS, RCDSO, on 2026-10-19. Dr. Kaur is a general dentist in Toronto (Bloor West Village) registered with the Royal College of Dental Surgeons of Ontario.
Yes. Plain, unflavoured sparkling water is far gentler on your teeth than soda, and the gap isn't close. The catch is the flavoured cans, which can behave a lot more like soda than like water.
In a lab study using real extracted teeth, sparkling mineral waters dissolved tooth mineral at levels roughly one hundred times lower than the soft drinks they were compared against (mineral water and erosion study, PubMed). That's a huge difference. Still, "gentler than soda" and "the same as tap water" aren't the same claim, so here's where the line sits.
What gives? Isn't fizzy water acidic too?
Most people think the bubbles are what hurts teeth. Here's what happens instead.
Carbonated water is plain water with carbon dioxide gas pushed into it under pressure. Some of that gas reacts with the water to form carbonic acid, a weak acid, which nudges the pH down. A chemist at McGill's Office for Science and Society tested 9 brands of carbonated water and found an average pH of 4.5 when they were cold and fizzy, the way most of us drink them (McGill OSS).
Enamel starts to lose minerals once the pH around it drops below roughly 5.5 (McGill OSS). A paper in the Journal of the Canadian Dental Association explains that this "critical pH" isn't a fixed number (Dawes, J Can Dent Assoc, PubMed). It shifts with how much calcium and phosphate is in the liquid around the tooth, including your saliva.
So yes, cold sparkling water sits a little on the acidic side of that line.
How far below the line it sits is the part that matters. Every drink in your fridge has a pH, and the soda on the next shelf is in a different league.
How acidic is soda compared with sparkling water?
A large study measured the pH of 379 drinks bought off store shelves (pH of beverages study, PubMed). The researchers sorted them into three zones based on how readily tooth mineral dissolves at each pH: below 3.0 counts as extremely erosive, 3.0 to 3.99 as erosive, and 4.0 or higher as minimally erosive.
Here's how some familiar drinks landed in that study (PubMed):
- Regular colas measured about 2.3 to 2.4, among the most acidic drinks tested, right next to lemon juice at 2.25.
- Diet and zero-sugar colas came in around 3.0, still well below the minimally erosive zone.
- Tonic water measured 2.54. Tonic is a soft drink, not a sparkling water.
- Two imported sparkling mineral waters measured 4.96 and 5.25, in the minimally erosive zone (PubMed).
Do the bubbles themselves wear down your enamel?
Pretty much no. The research so far says carbonation on its own plays a small role.
In the extracted-teeth study from the opening, the scientists took a sparkling mineral water and let it go flat. The flat version dissolved less mineral, but the fizzy version's levels were already low to begin with. The authors concluded that carbonation "may not be an important factor per se" in how erosive a drink is (PubMed).
Dr. Joe Schwarcz at McGill puts it plainly: carbonic acid does form, but the water isn't in contact with your teeth long enough to damage the enamel (McGill OSS).
Temperature changes the pH too. In the McGill testing, every brand read less acidic once it warmed up and went flat (McGill OSS). Did you know about this? I'm not going to tell you to drink warm, flat sparkling water. That defeats the point of buying it.
Why are flavoured sparkling waters a different story?
The flavour usually comes with added acid. In the big pH study, citric acid was the acid added to drinks most often (PubMed).
A UK study tested a group of flavoured sparkling waters and found a pH range of 2.74 to 3.34 (flavoured sparkling water study, PubMed). In the lab, every one of them dissolved tooth mineral at a level similar to or greater than pure orange juice, a drink dentists already treat as erosive. Teeth soaked in them for 30 minutes showed surface changes consistent with erosion.
The authors' advice was blunt. Flavoured sparkling waters should be thought of as "potentially acidic drinks rather than water with flavouring" (PubMed).
To be fair, the evidence here isn't perfectly tidy. In the smaller McGill test, a lemon-flavoured brand landed close to the unflavoured average, and the other tested less acidic than some plain brands (McGill OSS). The McGill chemist only tested two flavoured waters, both lemon, and said more testing would be needed.
My practical read? Flavour itself isn't the villain. Added acid is. Check the ingredient list, and if you see citric acid or another added acid, treat the can more like a soft drink than like water.
Is diet soda any easier on your teeth than regular soda?
For cavities, yes. For erosion, not much.
Soda harms teeth two ways. Sugar feeds the bacteria that make acid and cause cavities, and the drink's own acid dissolves enamel on contact. Taking the sugar out solves the first problem only. Our post on energy drinks and teens' teeth walks through that same two-part damage in more detail.
Diet colas in the beverage study still measured around pH 3 (PubMed). One lab study that soaked enamel samples three times a day for a week found diet cola softened enamel more than regular cola did (diet vs regular cola study, PubMed). That's one small lab study, so I wouldn't build a rule on it. It does show "diet" isn't a free pass.
The Canadian Dental Association's position names sodas, sports drinks, energy drinks and fruit juices as drinks that can cause cavities and enamel erosion, "especially when consumed frequently and over time" (CDA).
What about the sparkling water study in the news this summer?
You may have seen headlines in July saying sparkling water is better for your teeth than soda. That story came from a graduate student's poster at a nutrition science conference, not a published paper.
The researchers had 20 adults drink a sugar-sweetened soda, a plain sparkling water, a calcium-fortified sparkling water and plain water, then tracked the pH of their saliva (American Society for Nutrition release, EurekAlert). Soda made the mouth the most acidic, and it was still lower than water 20 minutes later. Both sparkling waters caused a short dip, and saliva brought pH back near its starting point within 20 minutes.
Have no fear of the headline, but don't lean on it too hard either. The conference organizers themselves say these findings should be considered preliminary until a peer-reviewed paper comes out (EurekAlert). The lab evidence from the extracted-teeth studies is older, but it's peer reviewed, and it points the same way.
How do you drink sparkling water without worrying about your teeth?
Canada's Food Guide is on your side here. Its advice for making water your drink of choice says, "If you like some fizz in your drink, try carbonated water" (Canada's Food Guide).
A few habits keep the risk low:
- Pick plain over flavoured when you can, and read labels for added acid.
- Drink it, don't nurse it. How often acid touches your teeth matters as much as how acidic it is, which is why the CDA flags frequent drinking (CDA). A glass with dinner is a different exposure than a can sipped across a three-hour work session.
- Have it with food. Eating gets your saliva flowing, and saliva is your teeth's built-in buffer.
- Finish with a sip of tap water. The McGill chemist who ran the pH tests does this herself (McGill OSS).
- Mineral water may have an edge. In the extracted-teeth research, calcium in the water reduced how much tooth mineral dissolved (PubMed).
How would you know if acid is already wearing your enamel?
Erosion is quiet at first. Sensitivity is often the first thing people notice, a twinge with something cold that wasn't there before. Our post on what causes tooth sensitivity covers that twinge in more detail.
Teeth can also start to look more yellow as enamel thins and the darker layer underneath shows through. Our post on why teeth turn yellow even when you brush explains how that happens.
Here's the part every patient should hear. Enamel lost to acid doesn't grow back. The JCDA paper explains why a white-spot cavity can sometimes remineralize while teeth eroded by acid cannot (PubMed). Our post on whether a cavity can heal itself explains the difference.
In about 25 years of practice in Bloor West Village, the pattern I see most isn't one heavy habit. It's the all-day sipper, with a can on the desk from nine to five. Some days the schedule runs tight, and I still make time to ask what's in that can, because the answer changes my advice.
Frequently Asked Questions
Q: Is sparkling water bad for your teeth? Plain sparkling water is mildly acidic but far gentler than soda. In a lab study with extracted teeth, sparkling mineral waters dissolved roughly one hundred times less tooth mineral than the soft drinks tested (PubMed).
Q: Is flavoured sparkling water worse for teeth than plain? Often, yes, because many flavoured versions contain added acid. One study found flavoured sparkling waters with a pH between 2.74 and 3.34 dissolved tooth mineral at levels similar to or greater than orange juice (PubMed). Check the label for citric acid.
Q: Is diet soda safer for your teeth than regular soda? Safer against cavities, not against erosion. Diet colas still measured around pH 3 in a large beverage study, well below the pH 4.0 line the study used for minimally erosive drinks (PubMed).
Q: Does carbonation itself damage enamel? The evidence says carbonation isn't a big factor on its own. Letting a sparkling mineral water go flat did reduce its effect, but its levels were low to begin with (PubMed).
Q: Does Canada's Food Guide recommend sparkling water? Yes. Its advice on making water your drink of choice suggests trying carbonated water if you like some fizz (Canada's Food Guide).
Q: Can enamel worn away by acid grow back? No. Early white-spot cavities can sometimes remineralize, but teeth eroded by acid cannot (PubMed). Protecting the enamel you have is the whole game.
Reviewed by Dr. Abinaash Kaur, B.Sc., DDS (University of Toronto Faculty of Dentistry), who has practised general and family dentistry in Bloor West Village for about 25 years. This article is general oral health information, not a diagnosis, medical advice, or a substitute for an examination.
Noticing new sensitivity, or wondering whether your sparkling water habit is leaving a mark? We're at 750 Annette Street in Bloor West Village, serving the Junction, High Park, and Baby Point. Book an exam with The Village Dentist and we'll take a look at your enamel and talk through what you're drinking.
