Bacteria sticks to food debris in the teeth, causing decay.

细菌附着在牙缝中食物残渣上，道致蛀牙。

Most of those scientists, including Levy, still support water fluoridation as a proved method of controlling tooth decay, especially in populations where oral hygiene is poor.

不过，包括李威在内大部份科学家仍然支持饮水加，是在口卫生较区，因为这是证明可以控制蛀牙方法。