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Speaker 1: Welcome to brain Stuff from house stuff works dot com

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Speaker 1: where smart Happens hi Immercial Brain with today's question, what

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Speaker 1: is a cavity in a tooth and why do they

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Speaker 1: drill it? There are three parts to any tooth. There's

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Speaker 1: the outer very hard enamel. There's the inner much softer denton,

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Speaker 1: which is like ivory, and then there's the core pulp,

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Speaker 1: consisting of nerves and blood vessels. When you get plaque

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Speaker 1: on your teeth, what you're getting is a film of bacteria.

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Speaker 1: These bacteria stick to your teeth, and one of the

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Speaker 1: things they do is create acid as a byproduct of

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Speaker 1: their metabolism. The acid can eat through the enamel of

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Speaker 1: the tooth and cause a cavity, that's a hole through

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Speaker 1: the enamel. Once the acid breaks through the enamel, bacteria

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Speaker 1: invade the denton and can start to eat through it

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Speaker 1: fairly quickly if they make it to the pulp. That

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Speaker 1: is when you get a tooth infection, and then you

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Speaker 1: need a root canal. When a dentist drills a tooth,

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Speaker 1: what he or she is doing is shaping and opening.

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Speaker 1: The first reason to do this is to make sure

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Speaker 1: that all the rot in the denton is completely removed.

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Speaker 1: The second reason is to create a shape to which

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Speaker 1: the filling can bond and feel completely. For more on

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Speaker 1: this and thousands of other topics, does it how stuff

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Speaker 1: works dot com and don't forget to check out the

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Speaker 1: brain stuff blog on the house stuff Works dot com

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