Actually teeth have nerves by accident. The nerve is inside the tooth because it became trapped there after the construction of the tooth. read more
So the evolutionary reason for teeth to have nerves is that the nerve is required to make the tooth in the first place. BTW this process is similar to the manufacture of other skin appendages, like hair and fingernails. read more
Same reason you have nerves anywhere within you- let you know if you're experiencing pain, because, evolutionarily, those who avoid pain prove to be more fit. I suppose dental nerves probably aren't as sensitive as, for example, those in the skin, but they still would serve the same purpose. read more
Tooth nerve pain - let s look at the basic anatomy of the tooth to understand the reasons why there are so many different causes for the pain. read more