Most of the hard black material where the teeth and gums meet is tartar. The black hard substance at the junction of teeth and gums refers to the embedded soft tartar that exists during eating, which is not brushed and cleaned in time, and the salivary minerals contained in it calcify and lead to the formation of tartar. If not dealt with in time to stimulate the gum tissue, it is likely to produce gingivitis, stimulate the tooth tissue and thus produce caries. Teeth and gums meet with black hard material, if it is soft scale can be brushed clean by cleaning and maintenance, but if it is calculus can not be brushed clean, you need to go to the hospital to deal with, you can use scaling to clean up. So, usually develop good oral hygiene habits, brush your teeth on time. Patients who have black hard objects at the junction of teeth and gums are recommended to go to the hospital in time for examination and standardized treatment under the guidance of the doctor.