A research by anthropologists found that, when analyzing the human remains, in the collected tooth samples, dental damage was closely related to the times. In older ages, the human teeth in the primitive era were healthier than in the present era. From the tooth remains of the Hunter Age, the tooth decay rate was 1-2%; 3-5% in the New Stone Age; the rate climbed to 11.7% in the Bronze Age; followed by 16% and 14.2% for Roman Empire and Middle Age respectively. In the present era, the rate is even up to 17.1%.^

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It should be easily understood that, since humans entered the agrarian era, they started a “high-carb diets”living. According to the molecular structure, carbohydrates can be divided into fiber, polysaccharides, oligosaccharides, disaccharides and monosaccharides. The disaccharides and monosaccharides formed after decomposition of these carbohydrate foods are the breeding ground of bacteria causing tooth decay. They also form acidic substances after digestion. When the teeth are not cleaned thoroughly, it will lead to various dental and oral problems. That’s why the present tooth brushing methods need to keep pace with times, so that we can have healthy teeth.