Tooth enamel is ~5 on mohs scale. Quartz, the most common kinda rock (afaik), is ~7.
Fun fact, this is why we know ancient people used to make bread - the way they separated wheat from the chuff included dropping it on the ground, which led to sand being in the bread and consequently destroying their teeth over a lifetime of eating it.
Well, rocks in toothpaste would be very bad because they’d be harder than your teeth.
Harder? No. Enamel is harder than steel. It is more brittle though so don’t go chewing rocks.
Tooth enamel is ~5 on mohs scale. Quartz, the most common kinda rock (afaik), is ~7.
Fun fact, this is why we know ancient people used to make bread - the way they separated wheat from the chuff included dropping it on the ground, which led to sand being in the bread and consequently destroying their teeth over a lifetime of eating it.
Tiny bits of rock and shells is how ancient people kept their teeth clean, that and not consuming sugar every minute