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    Teeth

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    George
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    Posts : 186
    Join date : 2017-11-26

    Teeth

    Post  George on Wed 07 Feb 2018, 19:37

    I have just watched a fascinating video by TED-Ed on the evolution of teeth (lesson by Peter S. Ungar).



    Teeth have the remarkable property that they are both hard and tough. Few substances are like that – for instance, glass is hard but not tough, while leather is tough but not hard. The hardness is due to an outer layer of enamel, produced by cells called ameloblasts, while dentine, produced by odontoblasts, confer the toughness. Dentine can be repaired when damaged, but enamel cannot be regenerated as the ameloblasts die after depositing the material. This is why tooth decay can be a serious problem.



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    Harald

    Posts : 15
    Join date : 2017-12-02

    Re: Teeth

    Post  Harald on Fri 09 Feb 2018, 13:00

    The real problem starts when both enamel and dentine are damaged, allowing bacteria to enter the breach and reach the pulp, which contain nerve fibres and blood vessels. A tootache is no joke – it really hurts. Sad

    In the episode “Omnishambles” of the current series of QI, it is mentioned that redheads are more sensitive to pain than non-redheads – which is why redheads visit the dentist less often than non-redheads. Rolling Eyes

      Current date/time is Sat 23 Jun 2018, 02:32