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.
Bacteria use the energy in the sugar and then make acids which attack teeth and tooth enamel. This then causes tooth decay, which is also known as dental caries. Bacteria in also found in dental plaque and that stick to our teeth, also causing tooth decay.