Pain in a molar tooth is usually caused by a cavity, infection, or irritation of the tooth. Try rinsing your mouth with warm saltwater to ease discomfort and keep the area clean, and avoid chewing on that side so it does not worsen the pain. You can place a cold pack on your cheek to reduce pain and swelling, and keep your mouth clean by gently brushing around the tooth after meals. Notice if the pain becomes sharp, constant, or if swelling or fever develops, as these can suggest a deeper problem. Consult a dentist who can examine the tooth and advise on the appropriate treatment for relief.