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 is the result of bacteria in the mouth, and its reaction to sugars and starches. As bacteria break down the sugars and starches, sticky plaque filled with acids form over the tooth. If left unchecked, plaque can form tartar, which cannot easily be brushed away.