Sensitive Teeth:
"If you have ever felt a painful sensation in your teeth after drinking or eating hot or cold food and beverages, you've experienced tooth sensitivity.  This is a condition that effects one out of every four adults".

"The common cause of sensitive teeth is exposed roots due to receding gum lines.  These roots are not covered by the protective enamel.  As a result, thousands of microscopic channels are exposed leading directly into the pulp,  the tooth's nerve center.  When heat and cold touch these channels they direct the sensation into the pulp and cause pain.  If you have pain let your dentist know.  Usually it can be treated through the use of a brush-on prescription fluoride gel or an anti- sensitive toothpaste."