The correct term for tooth decay is caries, daily brushing still appear caries may be incorrect brushing, there are caries risk factors, etc., as follows. 1. Incorrect brushing: the correct way of brushing teeth should use bass brushing method, place the toothbrush with the long axis of the teeth at an angle of 45 ° in the teeth and gums junction, so that a part of the bristles into the gingival sulcus, gently pressurized, the horizontal trembling of 4 ~ 5 times, each time brushing 2 ~ 3 teeth. It is recommended to brush teeth 2~3 times a day for more than 3 minutes each time. 2. Existence of caries risk factors: such as deep sockets, fixed or removable dentures, orthodontic brackets, the presence of overhanging bad restorations and other oral local factors can increase the incidence of caries. There may be other reasons for caries even if you brush your teeth every day, so it is recommended that you go to the hospital in a timely manner to get a clear picture of the cause of the caries and then undergo targeted treatment.