Hospital emergency rooms are not equipped to handle dental emergencies. The ER can provide painkillers or antibiotics but the tooth problem will not go away until it has been addressed by a dentist. If the pain is severe, take an over-the-counter pain reliever to make it manageable until you can get an emergency dental appointment. You should not go to a hospital emergency room for tooth pain unless you have also suffered some other kind of physical trauma that needs to be taken care of by a hospital.