In 1981, Reagan persuaded Congress to reduce the top tax rate form 70% to 50% and to index tax brackets (so that inflation was taken into consideration). In 1986, the Tax Reform Act reduced the rate on the wealthiest Americans to 28%.
Causes. Cavities are caused by tooth decay â a process that occurs over time. Here's how tooth decay develops: 1  Plaque forms. 2  Your mouth naturally contains many types of bacteria. 3  Some thrive on food and drinks that contain certain forms of sugar.
A cavity (say: KA-vuh-tee) develops when a tooth decays (say: dih-KAZE), or breaks down. A cavity is a hole that can grow bigger and deeper over time. Cavities are also called dental caries (say: KARE-eez), and if you have a cavity, it's important to get it repaired.