Welcome to brain Stuff from house stuff works dot com where smart Happens hi Immercial Brain with today's question, what is a cavity in a tooth and why do they drill it? There are three parts to any tooth. There's the outer very hard enamel. There's the inner much softer denton, which is like ivory, and then there's the core pulp, consisting of nerves and blood vessels. When you get plaque on your teeth, what you're getting is a film of bacteria.
These bacteria stick to your teeth, and one of the things they do is create acid as a byproduct of their metabolism. The acid can eat through the enamel of the tooth and cause a cavity, that's a hole through the enamel. Once the acid breaks through the enamel, bacteria invade the denton and can start to eat through it fairly quickly if they make it to the pulp. That is when you get a tooth infection, and then you
need a root canal. When a dentist drills a tooth, what he or she is doing is shaping and opening. The first reason to do this is to make sure that all the rot in the denton is completely removed. The second reason is to create a shape to which the filling can bond and feel completely. For more on this and thousands of other topics, does it how stuff works dot com and don't forget to check out the brain stuff blog on the house stuff Works dot com
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