You're also not allowed to have the best toothpaste in the world. Toothpaste with Novamin can't be sold in the US. Thankfully the internet makes it easy to get the good stuff anyhow.
That's a single metareview paper which was started by an undergraduate. Maybe people find that valuable, but other studies on the topics that used actual experimentation present somewhat mixed reviews trending towards clinical relevance.
In addition to choosing the toothpaste, it’s important to use the right brushing technique and schedule, which is critical since toothpaste does the bulk of the work after the physical process of brushing is done: don’t rinse with water (just spit instead) and arrange brushing so that you don’t eat or drink afterwards.
I just picked up some CariFree CTx4 Gel 1100. It has Nanohydroxyapatite, Fluoride, and Xylitol.
I'm actually quite annoyed that none of the half dozen dentists I've seen in the last 15 years have mentioned Nanohydroxyapatite as a compliment to fluoride.
Thanks for the recommendation, I had never heard of it. And I had the same experience in regards to the hydroxyapatite. No dentists told me, I just discovered it on pubmed and then went googling like crazy.
"NOTE: BioMin® F is not currently available for sale in the US. Although the Fluoride levels in BioMin® F are well below OTC levels in normal toothpaste, Flouride is classified as a drug in the US and has not yet been approved by the FDA."
“…concluding that there are no significant difference of remineralization process obtained by using traditional toothpaste and Novamin.”
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7068624/