Four fillings in six years, and every dentist told me I was doing everything right. One finally explained why both things were true.

I am not a dental person. I am a forty-four-year-old man who assumed that if you brush twice a day and floss most nights, the subject is closed. For most of my thirties it seemed to be.

Then, over about six years, I had four fillings. Not one dramatic disaster — four small, boring repairs, spaced far enough apart that each one felt like bad luck rather than a pattern.

What I could not get past was the conversation that came with every one of them. I would ask what I was doing wrong. And I would get some version of: nothing, really. You brush well. Your gums are healthy. Some people are just more prone to it.

That answer is kind. It is also useless, and I now think it is not quite true.

What I tried, in order

Because of course I did not leave it alone. In roughly this sequence:

1. Brushing harder. Which achieved a receding gum on the upper left and a cold-sensitive tooth I still have.
2. A better electric brush. Genuinely good. Made no difference to the count.
3. Flossing every night instead of most. Better gums. Same fillings.
4. Whitening toothpaste, then whitening strips. Teeth looked brighter for a while. Two weeks of sensitivity. Nothing else changed.
5. A stronger mouthwash. This is the one I want to come back to, because it turned out to be the most counterproductive thing on the list.

Five things, all of them sensible, all of them recommended to me by somebody. Not one of them touched what was actually going on.

The conversation that changed it

The explanation eventually came from an implantologist — a dentist who does not repair teeth for a living but replaces them, which I suspect is why he thinks about the start of the process rather than the middle.

He asked me one question that nobody had asked before: not how I was brushing, but when I was eating.

Then he explained the thing that, once I had heard it, I could not believe had never been said to me in twenty years of appointments.

Brushing is mechanical. The damage is chemical.

Bristles scrape plaque off a surface. That works. But the process that ends in a filling is not scraping — it is dissolving. Enamel is a mineral, and minerals dissolve in acid.

There is even a number. Below a pH of about 5.5, enamel starts giving up mineral. Above that, mineral moves back in. It is a two-way exchange that runs every day of your life, and the only thing that has ever mattered is which direction runs more often.

Then he asked me to count my day

Coffee at seven. Breakfast at half seven. Second coffee at ten. Something at eleven because I had skipped lunch the day before. Lunch at one. An afternoon coffee. Dinner at eight.

Seven occasions. He explained that each one opens roughly a forty-minute cycle: five minutes for the pH to fall, fifteen or so underneath the line, twenty for saliva to bring it back up.

And it does not have to be sweet. The coffee counts. The sparkling water I drank all afternoon at my desk counts. The glass of wine counts.

Then he pointed out the thing that made me feel slightly stupid. I brushed at seven in the morning and eleven at night — the two moments of the entire day furthest away from every single one of those windows.

I was not doing it wrong. I was doing it at a time when nothing was happening.

And the mouthwash was making it worse

This is the part I am still slightly annoyed about.

I had been using a strong rinse specifically because I thought I needed more protection. He asked me to read the ingredients. It was built on alcohol.

Alcohol dries the mouth. Saliva is both the buffer that brings the pH back up and the fluid that carries mineral back into the surface. So the product I had bought for protection was reducing the one thing that was actually protecting me.

It also explained something I had never connected: why my breath was fine for an hour after using it and then, by mid-morning, was not.

What I actually changed

Almost nothing, which is why I was sceptical.

1. I kept brushing twice a day. He was firm about this. Bristles remove plaque and nothing else does.
2. I stopped nursing drinks. If I want the sparkling water, I drink it. I do not sip it for an hour.
3. I stopped the alcohol rinse.
4. I added three seconds after eating. Two or three sprays, at the teeth and the tongue, held for five seconds. No water, no sink, no spitting.

That last one is the only thing I added, and the only reason I could actually keep doing it is that it needs no bathroom. It is in a jacket pocket. I have used it in a car park, at a desk, and once, honestly, in a lift.

What is in it, in plain terms

Two ingredients doing two jobs.

Hydroxyapatite is the mineral enamel is made of — so when acid takes mineral out, this is the same material being offered back, rather than a substitute or a coating.

Xylitol deals with 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 gives them nothing.

No fluoride. No alcohol. Safe to swallow, which is the whole reason it works away from a sink.

What happened, honestly

The numbers, since I am not evidence

I am one person and one person is a story, not a study. So here are the figures the company records — the first measured in a laboratory, the other three from users over four weeks.

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.

The whitening one is the one I would explain carefully, because it is not what people assume. Nothing is being bleached. A surface with fewer microscopic pits holds less pigment and reflects more light. That is why it comes with less staining rather than with the two weeks of sensitivity I got from the strips.

Dr. Toni Martinčević, DMDImplantologist · developed CariSpray

Skip, pause or cancel the delivery option at any time. No minimum, no fee. I am on the delivery option for an unromantic reason: the entire idea depends on it being there after meals, and it is not there if the bottle ran out on Tuesday.

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. Milgrom P. et al. — xylitol and Streptococcus mutans, PubMed
4. Published literature on salivary flow, xerostomia and alcohol-containing mouthrinses
5. CariSpray Clinical Prescribing Guide (EU), OralAdvance Labs — the four measured figures and the dermatological patch test