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.
Related Conditions. Cavities are a result of poor oral hygiene and retained dental plaque on the tooth surface. Specific bacteria in plaque cause decay. Different types of bacteria in plaque, retained near the gum line, cause gum disease to occur, which is a condition that your dentist and periodontist can help treat.