Use a hard bristle toothbrush as this can damage the soft tissues in the gums.

别用硬毛牙刷。硬毛牙刷会伤害牙龈组织。

youdao

The only sonic toothbrush with a slim, angled neck, contour-fit bristles and ultra-high bristle speed for greater plaque removal in hard-to-reach areas.

唯一的角度颈部声波牙刷苗条，轮廓，适合猪鬃和超高鬃地区高速到达的大斑去除硬的。

youdao