Sugar can cause tooth decay by being used as a food source for the bacteria found on our teeth, which causes plaque.

糖通过被那些存在我们牙齿的引起斑块的细菌作为一种食物来源，可以导致牙齿腐烂。

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When not removed, plaque causes tooth decay and gum disease.

牙斑没有清除就会导致蛀牙和牙龈疾病。

《柯林斯英汉双解大词典》

If left untreated, decay goes deeper and deeper into the tooth.

如果不及时治疗，蛀牙会越来越深。

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As the bacteria responsible for the tooth decay are sealed in, and deprived of nutrients, the act of sealing the decaying tooth with the metal cap should prevent the decay from spreading, at least until the baby tooth is shed at around 10 years of age.

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The German chemical giant BASF is working on a toothpaste that will not only resist tooth decay--the familiar ad slogan--but reverse it by rebuilding tooth enamel.

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It also attacked Streptococcus mutans, an acid-producing bacterium which is a major cause of tooth decay.

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