Below you can find the Communities adding this preventative to their water supply have reported up to 70 percent declines in tooth decay Jeopardy Words Answer. The answer to Communities adding this preventative to their water supply have reported up to 70 percent declines in tooth decay has 8 letters. This clue belongs to the Dentistry category and is part of Jeopardy Word Level 1177. If you scroll near the bottom you will find other clues and answers part of level 1177