Sugar solutions on the surface of exposed dentine cause water to be drawn out of the dentinal tubules causing which distorts the odontoblast causing pain.
[医务英语]《专业语—口腔生理学语O2(英文详解)》正文: Osmotic pressure - Water tends to move towards dense concentrations of ions.
If you're picturing skin covered in human teeth - just stop, that's terrifying These " skin-teeth" were really more like bumps made of dentine, which is the hard tissue found underneath the enamel of your teeth.
Because this surface is made up of many teeth, and the outer enamel layer of the tooth would wear down slower than the inner dentine layer, the teeth themselves, would wear down at an uneven rate.