If you keep chewing to avoid your cavity, it will wear down the other teeth around it more.
If you keep chewing to avoid your cavity, it will take its toll on the other teeth around it.
確かにその通りですよね。
何かを続ける ＝ keep 動詞＋ing 〜
何かを続けたら ＝ if you keep 動詞＋ing 〜
虫歯 = cavity; tooth decay
咀嚼 = chewing
「虫歯を庇った咀嚼 」= "chewing to avoid your cavity"; "chewing to protect your cavity"
負担がかかる = (この文脈では）wear down; take its toll
周りの歯 = the (other) teeth around it
アメリカ合衆国 
