Please choose the correct ending to complete the given sentence: Health: [header] How to avoid gum disease problems [title] Brush your teeth at least twice a day. [step] One major way you can avoid a buildup of plaque on your teeth is brushing your teeth twice a day, once in the morning and once before bed. You may also brush your teeth after meals to make sure there are no food particles stuck in your teeth.

Ending1: [substeps] Frequent brushing is good for those with dry or chapped gums, who like to use toothpastes or mouthwashes. You can also floss at least three times a day to keep your teeth from getting too dry, especially between meals. Ending2: [substeps] Brushing helps to prevent plaque buildup and prevent swelling in your gums. This can also repair gum mucous and reduce plaque in your mouth. Ending3: Some people brush in the morning and some the night before. [substeps] If you feel up to it, it is probably a good idea to brush before bed and floss between uses. Ending4: Use a toothbrush with a soft bristle head and toothpaste that contains fluoride. [substeps] When you brush, move the toothbrush backwards and forwards in short, circular motions.

Answer format: ending1/ending2/ending3/ending4