he colorful series Item No.D9, has the spiral bristles, bringing fresh experience of brushing ,itâs more effective for removing tartar and dental plaque , The innovative elastic brush neck, which can adjust the bending angle, prevents gums from damage caused by excessive force . This toothbrush has the regular replacement of functional device , mentioned the people when he need to change the toothbrush. The dentists recommend replace the toothbrush at least each 3 month.Â