Pain in the upper tooth, along with mouth ulcers and a sore tongue, can be due to a dental infection, vitamin deficiency (especially B12 or iron), oral irritation, or sometimes a fungal infection. You can use a pain-relieving oral gel for ulcers, rinse with warm salt water, and maintain good oral hygiene. If symptoms last more than 1-2 weeks or keep recurring, consult a doctor for proper evaluation and treatment.