What can cause pain in teeth after sleep?

Grinding : If you are grining during sleep you can over stress the ligaments that hold the teeth into the bone and will make them sore. The muscles may spasm which can cause some refeered pain to the teeth and stffness in the jaw.

Various things: Night time dental pain can be caused by a change in blood flow in a tooth with an unhealthy nerve, or possibly from clenching or grinding your teeth.

Grinding/clenching: If you grind or clench your teeth during the night, in the morning you could have soreness or pain in your jaw, by the ear or in your teeth, visit your dentist for an exam and to determine if you need an occlusal guard / night guard to sleep at night.

Several things: The most common is grinding which a nightguard can alleviate. Nasal congestion w full sinuses( congestion) can also cause some tooth soreness. Many get congested when they have allergies and lay down.