填空题Questions 14-19 Answer the questions below using NO MORE THAN TWO WORDS from the passage for each answer. Write your answers in boxes ]4-] 9 on your answer sheet.
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What does fluoridation affect in order to prevent tooth decay?
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What do dental bacteria produce?
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When mouth pH goes below 5.5, what is dissolved?
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What does fluoridation form in the mouth to restore mineral density in teeth?
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What is the coating that demineralization forms on teeth?
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Through what mechanism does swallowed fluoride go to teeth?