Pulpitis is inflammation of the pulp chamber located in the tooth's center. There are various reasons that the center chamber may become inflamed. For example, you may have hit your tooth in the past or have decay reaching the pulp chamber. Whatever the cause is, the inflammation is a response of your body to try and heal the tooth because it senses a problem. The inflammation can create pressure in your tooth and often makes it sensitive to cold. However, for some people with pulpitis, lying down increases the pressure in the head and further increases pressure into the tooth. This pain will commonly manifest as a throbbing and aching in the tooth.

There are two degrees of pulpitis: reversible and irreversible. Reversible means the tooth may heal without treatment, and the condition will eventually disappear. Irreversible means the tooth won’t heal and need a root canal to save the tooth. A dentist can test this out for you or read this article on cold sensitivity.

In the meantime, over-the-counter ibuprofen three times a day for three days is one thing I tell some of my patients to do to reduce inflammation and pain. In addition, Ibuprofen can help reduce the possibility of reversible pulpitis progressing into irreversible. Finally, at night it is recommended to sleep with your head propped up to minimize the throbbing.

The next possibility of a toothache at night is clenching and grinding, known as bruxism. Clenching causes excess pressure on the ligaments that hold your teeth in place. The pressure triggers inflammation of the ligaments and causes your teeth to ache and throb. Involuntary teeth clenching usually happens at night when people sleep, but it can also occur during the day. Unfortunately, most people don’t realize they are clenching and grinding and night.

A slight pain that is difficult to locate is an indicating factor that you have excessive nighttime clenching. Further, people with bruxism pain commonly can’t even pinpoint the pain to the top or bottom teeth. Clenching and grinding will also manifest as a pain that only comes when chewing for some people or a spontaneous pain for others. A sign that you may clench and grind your teeth at night is if you have a lot of worn-down teeth with or without a lot of chipping and cracks.

Because the subject of clenching and grinding is vast, I have a whole article here on all the causes of it and TMJ, including how to find relief.