The choice of bristles should be soft and hard moderate, or slightly soft. But be careful, too soft bristles easy to brush dirty. Multi-purpose bristles made of nylon. Can be divided into two kinds - ordinary silk and Du Pont silk. DuPont wire elasticity is better, not easy to fall. Milling treatment is also important. After the bristles are cut, they are easily damaged by being too sharp if they have not been smoothed. Brushed bristles round grinding toothbrush to prevent this damage, stronger protective effect on the gums.