Please don't worry, cavities are very common and highly treatable. For early enamel decay, using a prescription high-fluoride toothpaste (containing sodium fluoride) can help remineralize and strengthen your teeth. However, once a physical cavity (a hole) has formed, toothpaste alone cannot reverse it. You will need to visit a dentist for a professional treatment, such as a simple dental filling to restore the tooth. For deeper decay, treatments like crowns or root canal therapy may be required. I recommend scheduling a dental check-up soon so a professional can evaluate your tooth and provide the right care. Meanwhile, keep brushing twice daily with fluoride toothpaste and flossing.