It is advisable to go to the hospital for a full mouth scaling to remove the calculus and plaque attached to the tooth surface. If there is calculus below the gums while scaling, subgingival scaling is also required. You should pay special attention to oral hygiene, brush your teeth on time every morning and evening, and brush your teeth for no less than three minutes, and if you have the conditions, you’d better use dental floss or a gap brush to clean the gaps of your teeth to avoid the fermentation of food residues and odor. If the bad breath is caused by tooth decay, the easiest way is to have a tooth filling. In addition, it is recommended to adjust the diet, regular work and rest time, do not stay up late, and try to eat less stimulating and strong-smelling food, such as onions, leeks, garlic, etc.