Three different effects on teeth
A sugary soft drink can contain both sugars and acids. Unsweetened tea can contribute to surface stains. To understand these examples, separate what feeds bacteria, what acts directly on tooth tissue and what colours the surface.
| Effect | What is involved | Example |
|---|---|---|
| Tooth decay | Bacteria in dental plaque turn sugars into acids that demineralise tooth tissue. | Sugary foods and drinks, particularly on repeated occasions. |
| Erosion | Acids act directly on tooth tissue, without being produced by bacteria. | Acidic drinks or sour sweets consumed frequently. |
| Surface staining | Coloured compounds accumulate on the outside of teeth. | Coffee, tea and red wine are examples. |
“Sugar-free” answers only one question
Consider three separate questions about a drink: does it contain sugars, is it acidic, and does it contain pigments associated with staining? A sugar-free soft drink can still be acidic. Fruit juice contains naturally occurring sugars and can also be acidic: “no added sugar” does not mean “no sugar”.
Tea and coffee with no added sugar are still examples of drinks associated with surface stains. Added sugar and pigments are therefore two separate pieces of information to consider when describing your usual drink and how you prepare it.
Record the exact product and the claim you want to understand. “Light”, “natural” or “detox” does not tell you about all three effects. An ingredient list cannot calculate an erosion risk for your teeth either.
Three everyday habits to look at
Both the amount consumed and repeated occasions matter. Ameli highlights sugary snacking, while the ADA notes that amount and frequency are linked. Consider both what you consume and when you have it.
- The French oral health organisation UFSBD advises limiting snacks and having sugary foods with meals when possible.
- Keep water available as your usual drink.
- Avoid holding acidic drinks in your mouth or swishing them between your teeth.
Juice, sugar-free soft drinks and tea: putting it into practice
Here is a fictional example: orange juice with breakfast, a sugar-free soft drink sipped through the afternoon and unsweetened tea after lunch.
For the juice, “no added sugar” does not remove the naturally occurring sugars. For the soft drink, the absence of sugar does not answer the acidity question; prolonged sipping adds useful context. For the tea, pigments can still contribute to staining.
This example does not rank the three drinks by harm. It shows which questions to ask. To look back at your habits, a note of the drink and the occasion is enough. A colour change in a photo cannot establish that one of these drinks caused it.
Sources and further reading
- UFSBD — Alimentation : manger sain et équilibré (août 2024)
- Assurance Maladie — Les produits sucrés (24 juin 2024)
- American Dental Association — Nutrition and Oral Health
- American Dental Association — Dental Erosion
- American Dental Association — Whitening (section Extrinsic vs. Intrinsic Stains)
General information for adults, prepared by the Enamel team from the sources above. Not clinically reviewed. Ask your dentist for advice specific to your teeth. Our editorial approach.