Mouth garden

The garden needs JavaScript, which appears to be switched off. The idea it teaches is in the pillar guide.

Feed the garden, brush it, floss the gaps, scrape the tongue — or try to nuke it clean and watch what grows back first. For most of the last century oral health was explained as a war: bacteria cause cavities, so kill bacteria. The pillar guide this game is built on says that story is simple, memorable and mostly wrong, and the game is a way of finding that out by hand. The product that promises to kill everything is on the cards. It does exactly what it says.

What the garden is a picture of

Your mouth carries a permanent microbial community — the Human Oral Microbiome Database curates 836 taxa, 525 of them primarily oral — and almost none of it is trying to hurt you. A healthy mouth is not a sterile one; it is one where that community is balanced, and where the species that cause trouble are kept in check by the ones that do not. The game reduces hundreds of species to three colours: green for the ordinary residents, coral for the acid-makers that only thrive when fed sugar, and a grey moss for the sulphur-makers that live at the back of the tongue and make breath. The needle you are keeping in the green band is a crude diversity measure. It cannot be pinned to the sterile end, because a garden with nothing in it is not a healthy garden; it cannot be pinned to the coral end, because that is what cracks stones. The whole of the pillar guide is the long version.

Why mouthwash looks like it works

Play the alcohol mouthwash card and the garden clears. Ninety per cent of everything is gone, the breath meter drops, the needle swings towards sterile and for a moment it looks like the cleanest mouth you have had. Then watch. Bare cells are an opportunity, and the fast-growing acid-makers take them first. The mouthwash article puts it in one sentence: broad antiseptics “do not distinguish between the species causing gum disease and the ordinary residents holding territory against them. Clearing the ground does not obviously favour the side you want.” The game gives coral a three-fold advantage on bare soil for six hours after a wipe. That number is the game’s, chosen so the lesson lands inside a thirty-day run; the direction is the article’s, and the article is careful that the strongest rinse, chlorhexidine, is a short-course treatment, not a toiletry. See is mouthwash bad for you? for the three kinds and what each is for.

Why five sips beat one glass

Every time sugar reaches plaque, the bacteria in it produce acid within minutes and the pH at the tooth surface falls; below roughly 5.5, enamel starts giving up calcium and phosphate. Saliva then buffers the acid and brings the pH back over about half an hour. The gauge on the HUD is that curve — the Stephan curve — and the game charges you a full recovery window for every separate mouthful, which is why the sipped fizzy drink is five dips and the drunk one is one. That is the frequency-over-quantity finding from can teeth remineralise?: a 2019 review in Caries Research concluded that reducing the amount without reducing the frequency does not seem to be an effective way to prevent decay, and a 2026 systematic review found frequency the stronger determinant. Mineral that comes back between dips is remineralisation, and fluoride helps it along — which is why the fluoride brush card boosts recovery for twelve hours. A stone that runs out of mineral cracks, and the crack stays, because once a cavity has broken through the surface nothing closes it.

What the month throws at you

The thirty days are not random. Each stretch is a picture of one thing the site has written about, and the card that looks like the easy answer is usually the one the article warns about. The week is the month compressed: one birthday, one advert day, one dry day, no cold and no appointment.

• Day 3, the birthday. Cake now, cake then sweet tea sipped for an hour, or gum. Same sugar, one dip or five: the frequency finding from can teeth remineralise?
• Day 5, a blocked nose. Mouth breathing overnight, so the night grows twice as fast — why morning dryness is worse than daytime, from dry mouth.
• Day 7, the cold. An antibiotic course you have to take, then a bare garden and a lozenge that fades unless the community is already yours: the pillar guide and do oral probiotics work?
• Days 10 to 13, the advert. Mouthwash in every moment, and it is offered in the morning whenever the breath meter is high. The scraper is the answer; the rinse is the trap: is mouthwash bad for you? and tongue scraping.
• Day 14, Saturday night. A late snack and a bed that is very close. Skipping the night brush leaves everything on the teeth to grow all night.
• Days 17 to 19, new medication. Dry days. Water shortens a dip, plain sparkling water is fine, flavoured sparkling water is on the acid list: enamel erosion.
• Days 21 to 24, grazing week. Six food moments a day. Half a biscuit now and half later costs two windows, not one.
• Day 22, the appointment. One dental cleaning in the month, and it is not a card you choose. Scaling takes the hardened deposits a brush cannot reach; it does not touch the tongue, put mineral back or close a crack. How often anyone needs it depends on their risk, not on a calendar, and the month here is compressed: what a dental cleaning does.
• Days 26 to 28, exam week. Sugary coffee at every turn. Gum and water are the way through.

What the game gets wrong on purpose

• One thing per moment. Real mornings hold a brush and a scraper. The game makes you choose so that the choice teaches something: what each tool reaches, and what nothing else does.
• Scale. Three species stand in for several hundred, and fourteen teeth — seven above, seven below — for thirty-two. The tongue’s sulphur-makers are real (what causes bad breath?); their being one uniform moss is not.
• Speed. A day is a minute, a pH dip is a second and a quarter, and a stone cracks in days. Cavities take months to years, which is exactly why the two-day habits matter more than any product.
• The mouthwash number. The three-fold regrowth advantage is a tuning constant, not a measurement. The article’s claim is directional, and the game keeps it directional.
• Tongue scraping. The meter creeping back within about thirty minutes is faithful to the trials — the reduction in sulphur gases “could not be detected for more than 30 minutes after the intervention” — but in the game thirty minutes is a second, which makes scraping look more futile than the article concludes it is.
• Probiotics. The lozenge’s green patch fades in two days unless conditions favour it, because colonisation is usually temporary. Real trials are a few dozen people over a few weeks; the article has the numbers.
• Everything is instant. Brushing thins colonies in a frame; flossing empties a gap at once. Both are honest about where they reach — the brush never touches the gaps, and nothing but floss does — and dishonest about how completely.

This is a game about one idea, not advice about your mouth. Nothing here is medical or dental advice; see a dentist about your own teeth, particularly for pain, bleeding or anything that has changed.

Our illustrations and tools are free to reuse under CC BY 4.0 — see the diagrams page.