Dental fillings that fall out are required to be re-prepared and polished. If a filling falls out and you want to fill the tooth again, you will need to have the cavity prepared and polished again. This is because the filling may have fallen out because it did not fit the cavity properly, and the filling was not well anchored in the cavity and fell out. Moreover, after the filling falls out, the cavity will be contaminated by saliva, so if you need to fill it again, you will need to prepare and polish the cavity again. If the filling falls out and is not prepared and ground again, the filling may fall out more easily because the cavity is already contaminated with saliva and bacteria are sealed in the cavity. Bacteria may even erode deeper into the tooth, causing pulpitis. After the filling has fallen out of the tooth, it is advisable to visit a dental clinic in time for further treatment by a professional doctor.