How many acid windows do you open a day? Eight questions, and the answer is usually higher than people expect.

Enamel is a mineral, and minerals dissolve in acid. Below a pH of about 5.5, enamel starts giving up mineral. Every time you eat or drink anything, plaque bacteria push the mouth under that line for roughly twenty minutes before saliva brings it back up.

That is an acid window. This check counts yours. It takes two minutes, nothing is stored and nothing is sent anywhere — the arithmetic runs in your own browser.

What the score is measuring

Not how well you brush. It has almost nothing to do with technique, and that is deliberate.

It is counting three things: how many times a day the mouth goes under the line, how long each of those windows stays open, and whether anything at all is present when they do.

Question 2 carries as much weight as question 1 for a reason. The Vipeholm work established it decades ago and it is still the least-repeated fact in the subject: the number of separate occasions matters more than the total amount. A coffee drunk in ten minutes is one window. The same coffee nursed for an hour is a window that never closes.

Question 5 is there because saliva does two jobs at once — it buffers the acid back up, and it carries mineral back into the surface. Lose it and you lose both. Which is also why question 4 exists: a rinse built on alcohol dries the mouth, so a product bought for protection can reduce the fluid actually protecting you.

What actually goes back in

Enamel is not “calcium” in a general sense. It is built overwhelmingly from one specific mineral: hydroxyapatite. When acid takes mineral out of the surface, that is exactly the mineral it takes — so the idea is not a substitute or a coating, but the same material offered back, in a particle small enough to settle into the surface.

Xylitol handles the other half — the bacteria producing the acid. It resembles sugar closely enough that they take it up, and then cannot metabolise it. They fill up on something that returns them nothing.

And the format follows straight from question 7. A toothbrush cannot go to lunch with you, and a 500 ml rinse that has to be spat into a sink cannot either. So it had to work with no water, no rinsing and no sink — which meant it had to be safe to swallow — and it had to take three seconds.

What is actually measured

Four numbers, and it is worth being precise about where each one comes from. The first was measured in a laboratory. The other three come from users over four weeks of ordinary use.

It has also been dermatologically tested — a patch test on twenty adults with sensitive skin, recorded as non-irritant and non-sensitising.

What that adds up to

1. Mineral, not just cleaning. Hydroxyapatite is what enamel is made of. It is the one thing a rinse that only removes can never give back.
2. Whiter without bleaching. The whitening is a smoother surface holding less stain, not peroxide stripping the outer layer.
3. Breath that comes from the tongue, not from mint. Fewer of the bacteria producing sulphur compounds, and no alcohol drying the mouth out two hours later.
4. Less tartar. Reported by nearly three in four over four weeks.
5. Three seconds, anywhere. No water, no sink, no spitting, no rinsing — which is the only way anything can be used at the moment the acid window is actually open.
6. Safe to swallow. Which is what makes the point above possible at all.

Dr. Toni Martinčević, DMDImplantologist · developed CariSpray

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If you are still not sure

Every order carries a 60-day money-back guarantee, counted from the day the order arrives. Keep the bottle — sealed, opened or empty, there is nothing to send back. Email with the order number and the purchase price and original shipping are refunded.

Sixty days is roughly three hundred and sixty acid windows. That is long enough to know.

Sources

1. Dawes C. What is the critical pH and why does a tooth dissolve in acid? J Can Dent Assoc 2003;69(11):722–4
2. Gustafsson B.E. et al. — the Vipeholm dental caries study, on frequency of intake versus quantity
3. Published literature on salivary flow, xerostomia and alcohol-containing mouthrinses
4. Milgrom P. et al. — xylitol and Streptococcus mutans, PubMed
5. CariSpray Clinical Prescribing Guide (EU), OralAdvance Labs — the four measured figures and the dermatological patch test