Know the Tooth

The safest floss is one made from a natural fiber like silk, not plastic. Here's why. In recent years, there's been growing concern about dental floss containing PFAS, the so-called "forever chemicals." To help floss glide more easily between teeth, some manufacturers make floss from PTFE (the same fluoropolymer family as Teflon) or apply synthetic coatings. Some of these materials have been linked to PFAS exposure, and PFAS have been associated with a range of health concerns when they build up in the body.

Common signs of thinning enamel are teeth that look more yellow, surfaces that look smooth and glassy, small dents or cups on your chewing surfaces, new sensitivity to cold or sweets, chipped or rough biting edges, and fillings that seem to sit higher than the tooth around them. Enamel can't grow back, so noticing these early really matters.

Nano-hydroxyapatite is the same mineral your enamel is made of, made into very small particles. In toothpaste, it has good evidence for helping protect enamel and reducing tooth sensitivity. It has early evidence for keeping bacteria from sticking and for giving teeth a brighter look. And because it matches what your teeth are already built from, it works with your body, not against it.

You are holding two tubes. Both say 10% nano-hydroxyapatite. Are they the same? Most likely not. A percentage tells you how much of an ingredient is present. It says nothing about the quality of that ingredient, the shape and purity of the crystals, or the formula built around them.

Dentists tend to ask the same short list of questions about any toothpaste: what the active ingredient is, how much is in there, what the material is really like, what the evidence says, what the rest of the formula does, whether it suits the person using it, and whether the brand's claims are realistic.

Two tubes can both say nano-hydroxyapatite on the front and contain very different things inside. So look past the ingredient name. Check the concentration, how well the material is described, the purity of the crystals, the rest of the formula, and the research behind the benefit you are buying it for.

Glycerin is a humectant — it keeps toothpaste from drying out in the tube — and it mixes completely with water, so rinsing removes it. The claim that it leaves a film requiring dozens of rinses traces to a single self-published book from 1997 with no supporting data behind it.

Because a paste has to taste like something and hold up on a shelf, and if those jobs can be done by compounds with a plausible oral rationale rather than artificial flavors, that's a better trade.

For breath, modestly — and on thinner evidence than the internet suggests. Scrapers do reduce the sulphur compounds behind most bad breath slightly better than a toothbrush. For nearly everything else tongue scraping gets credited with, including cleaner teeth and "detoxing," there's no evidence at all. What does the evidence actually show? Less than you'd expect from how confidently it's recommended. The Cochrane review on tongue scraping for halitosis found only two trials, with 40 participants between them. Both showed a statistically significant reduction in volatile sulphur compounds — the gases behind most mouth-origin bad breath — using a scraper or cleaner rather than a toothbrush. The reviewers described that as "weak and unreliable evidence suggesting a small but statistically significant difference." And here's the detail that matters most: neither trial measured whether anyone's breath actually smelled better to another person. They measured gas with a sulphide monitor. So: scraping lowers a number that correlates with bad breath. Whether it changes how you smell to a colleague hasn't really been tested. Why the tongue, though? Because of the surface area. The back of the tongue isn't smooth — it's covered in papillae, a textured landscape holding a coating of bacteria, food debris and shed cells. Those bacteria break down proteins and release sulphur gases as waste. A toothbrush isn't shaped for that terrain, and most of the tongue never gets touched at all. Scraping removes the coating. It doesn't change which bacteria live there. What tongue scraping doesn't do It doesn't clean your teeth. Tongue coating and dental plaque are different communities on different surfaces; removing one does nothing to the other — that job belongs to brushing and interdental cleaning. It doesn't "detox" anything. The coating is bacteria and debris, not toxins leaving the body. And it doesn't reach bad breath starting elsewhere. Sinus and airway conditions, reflux and certain medications produce odour no scraper reaches. Persistent bad breath despite good hygiene is worth investigating rather than scraping harder. The part nobody mentions: your tongue bacteria have a day job The bacteria on your tongue convert dietary nitrate into nitrite — a step in the pathway producing nitric oxide, which supports blood vessel function. A 2019 study in Frontiers in Cellular and Infection Microbiology followed 26 adults for two weeks and found tongue-cleaning habits shaped this community, with daily cleaning enriching nitrate-reducing species. Genes for nitric-oxide-forming nitrite reductase were inversely correlated with systolic blood pressure (R = −0.7). The disruptive intervention in that study wasn't the scraper. It was seven days of antiseptic mouthwash. Mechanical cleaning is the gentle option — chemical sterilisation is the one with a documented downside. What this doesn't mean That study is small, ran 14 days, and its blood pressure differences were a couple of millimetres of mercury. It's a signal about mechanism, not a health outcome — and it doesn't make a tongue scraper a cardiovascular intervention. Where a toothpaste fits Nowhere near the tongue — no paste out-scrapes a scraper. What a formula can do is avoid adding to the problem. Dr. Jen leaves out SLS, which is associated with oral tissue irritation, and uses botanicals chosen for their properties rather than artificial flavour: black cherry extract for inflammation, papaya for antioxidants, licorice root for its soothing effect. Masking an odour and reducing its cause are different, and only one of them lasts.

They can be, but the nutrient isn't the problem, the delivery is. Chewable and gummy supplements hold acid and sugar against enamel for minutes at a time, while a swallowed capsule delivers the same dose with almost no tooth contact. The damage comes from contact time, not from vitamin C itself.

"Ozempic teeth" isn't a diagnosis — it's a nickname for a cluster of real problems showing up in people taking GLP-1 medications: enamel erosion from stomach acid, dry mouth, and frequent snacking to manage nausea. The drugs don't attack teeth directly. They change the conditions in your mouth, and the damage follows from that.

In simple terms, the bacteria that cause cavities can't tell xylitol from sugar. They pull it in and start processing it, then get stuck — xylitol isn't something they can use for energy. Now they have to spend energy pushing the waste back out. They end up burning fuel to take in something that feeds them nothing. Do that often enough and the population weakens.

Somewhat, but less than expected. A round monofilament touches the tooth along a narrow line. A multifilament thread flattens and spreads across a wider band. What no study has shown is that one material leaves teeth measurably cleaner than another.

Almost all dental floss is nylon or PTFE — the polymer family behind non-stick cookware — spun into a filament and coated with wax and flavouring. You won't find that written on the box. Floss is regulated as a medical device, so unlike toothpaste, it carries no required ingredient list. A few oral care brands still make silk floss, the original material today. An example is Dr. Jen.

An egg allergy is a reaction to egg proteins, and eggshell-derived nano-hydroxyapatite is a mineral made under heat high enough that no protein survives it. But "should contain none" is not the same as "was tested on you" — so if you have a diagnosed egg allergy, this is a conversation for your allergist.

Eggshell nHAp is nano-hydroxyapatite made from real chicken eggshells rather than built from scratch in a lab. The shells are cleaned, heated, and reacted with a phosphate source until their calcium becomes hydroxyapatite — the same mineral your tooth enamel is made of.

Your bone and the outer layer of your teeth are built from the same raw material. That material is hydroxyapatite — a calcium phosphate crystal. It makes up roughly 65–70% of bone by weight and the large majority of dentin and enamel. So when a dentist says you have "strong enamel," what they really mean is that a lot of hydroxyapatite is still packed into the surface of your teeth. 

Surgeons coat titanium dental implants and artificial joints with hydroxyapatite because bone doesn't merely tolerate this mineral, it grows into it. Hydroxyapatite is what bone and enamel are already built from, so the body responds to a coated implant as something to bond with rather than wall off. It's called biointegration.

Biomimetic means "copies biology." In toothpaste, it describes an ingredient built to match what your teeth are already made of. Nano-hydroxyapatite is the clearest example: it's the same mineral as your enamel, made at the same microscopic size so your teeth recognize it.