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.
Cavities: Holes or structural damage in the two outer layers of a tooth called the enamel and the dentin. The enamel is the outermost white hard surface and the dentin is the yellow layer just beneath enamel. Both layers serve to protect the inner living tooth tissue called the pulp, where blood vessels and nerves reside. Cavities are caused by bacteria in the mouth. Small cavities may not cause pain, and may be unnoticed by the patient. Larger cavities can collect food, and the inner pulp of the affected tooth can become irritated by bacterial toxins, foods that are cold, hot, sour, or sweet - causing toothache.