04/27/2026
I’ve spent the last few weeks reading papers I never thought I’d revisit since I quit dental school 16 years ago, and I have a lot to say about what I found.
What pulled me in was watching this play out in my own DMs. Mamas asking if they need to throw out the toothpaste they’ve been using for years because some Substack told them the active ingredient in it is silently destroying their family.
When I traced the viral piece back to its source, the disclosure was right at the top: sponsored by a brand that doesn’t use hydroxyapatite, author with no dental or scientific training and zero citations.
There’s been more drama on Instagram about nano-hydroxyapatite in the last six months than there have been documented adverse events in 45 years of Japanese clinical use. The 18-month adult trial had zero serious adverse events. The pediatric trial had zero. The safety profile is lighter than most things people put in their mouths twice a day.
That doesn’t mean it’s perfect. Most of the positive research is industry-funded, there’s no Cochrane review yet, and no RCT in kids under 3. I want to be honest about all of that.
But you don’t have to throw out your toothpaste because someone with a ring light told you to. The questions that matter aren’t “is this brand trending,” they’re “what’s the particle size, what’s the shape, and will the company tell me when I ask.”
I researched nano deeply because I wanted to know if it was safe for the people who do choose it (including a lot of you). For my own family right now, I’m sticking with micro because the under-3 evidence gap is important to me even though Honey isn’t using toothpaste yet, and Daniel and I don’t have the sensitivity issues that make nano worth the trade-off.
Comment TOOTH and I’ll send you the only two brands I personally trust for my family. Both pass the questions in this carousel. I want you to have an answer when the next viral panic comes for you. 🤍
