Below is an excerpt from an article found on Crest.com Common Toothache Causes Are you wondering why your teeth hurt? If you have aching teeth, it may be due to a dental problem such as cavities, gum disease, bruxism, TMJ or a non-dental problem, such as a sinus infection or even stress. Sensitive Teeth: Some types of toothache pain occur if you are using dental care products like peroxide-based whitening agents that penetrate into your teeth causing tooth sensitivity. Bruxism: If you have aching teeth with no signs of tooth decay or gum disease, you may be experiencing bruxism. Bruxism is the technical term for grinding your teeth. Bruxism is a common cause of aching teeth that affects millions of people of all ages in the United States. If you experience aching teeth and other symptoms of bruxism, see a dental professional as soon as possible. If left untreated, chronic tooth grinding can damage crowns and fillings, and wear away tooth enamel, putting your teeth at increased...