Mr. Zhang, a 38-year-old man, had been experiencing frequent bleeding gums and bad taste in his mouth for several months. He was very surprised when I told him after examination that it was caused by poor oral hygiene, dental calculus and plaque. Mr. Zhang said he was busy with business and socializing outside the number of brushing teeth is indeed a lot less, but chewing gum every day can not also clean the mouth? Indeed, chewing gum often can increase saliva secretion, so as to better clean the mouth and teeth and reduce the formation of plaque. And in repeated biting action, jawbone, bite muscle and teeth can be fully exercised, for periodontal health is very beneficial. However, chewing gum can only clean a small part of the tooth surface and gums, but it can not do anything for the food residue and plaque in the teeth and the neck of the teeth, and it can not replace brushing. Chewing gum contains a variety of fragrances, strong and long-lasting aroma, chewing can make the breath fresh, but this effect is temporary. Oral odor is caused by a variety of factors, should find the corresponding causative factors, is the fundamental way to maintain a fresh mouth. As we all know, most chewing gum is sweetened with sucrose. When chewing chewing gum, the sugar will stay in the mouth for a long time, and the cariogenic bacteria in the mouth will use the sugar to produce acid, which will corrode the teeth and cause the decalcification of teeth, thus inducing tooth decay. In addition, people who have had their teeth filled with mercury-containing materials should not chew gum, as this will release the amalgam and cause the mercury level in blood and urine to exceed the standard, thus causing harm to the brain, central nervous system and kidneys. In order to better protect our dental health, we must develop good brushing habits. When it comes to brushing your teeth, the first step is to choose a toothbrush that works for you, with a small head of soft bristles as appropriate. The correct brushing method will allow us to clean our teeth easily without causing damage to periodontal and dental tissues. Many people like to brush horizontally, which can easily damage teeth and gums. The correct way to brush teeth is to make the toothbrush bristles and teeth at 45 degrees, with the head of the bristles pointing in the direction of the gums, so that the bristles enter the gap between the teeth and the teeth, and some of the bristles press on the gums back and forth to a short distance back and forth chattering. This brushing avoids the disadvantages of horizontal brushing, while retaining the advantages of the strong ability of horizontal brushing to clean teeth. Secondly, brush your teeth following the 3-3 rule ① 3 times a day. ②3 minutes each time. ③Brush your teeth 3 minutes after meals. Brush your teeth as many times as it takes to thoroughly control plaque and tartar. Pay special attention to the quality of brushing, if the brushing time is not enough, it is also not enough to remove plaque completely. When brushing your teeth, brush each surface at least 5 to 10 times for 3 minutes each time. It is especially important to brush at night before going to bed because bacteria are easy to grow and multiply in a dark, warm and moist oral environment, and bacteria are more likely to multiply and breed at night when chewing, speech and other activities are reduced during sleep. Even if we brush our teeth thoroughly, we can only clean 75% of the tooth surface, and another 25% of the tooth surface, that is, the adjacent surface of the teeth, is not easy to be brushed by the toothbrush, and needs to be cleaned with the help of dental floss and toothbrush, so chewing gum alone cannot replace brushing.