Why is it that when i eat some sweet stuff like gummy candy or rich chocolate my teeth feel real sensitive to it like a slight ache for a second?

You may have a : sensitivity to sweets and need to see a dentist to assess your need for Fluoride dental work or other tooth related issues

Sweet sensativity : The sugar changes the flow of fluids in and out of the tubules in the root of the tooth. Like the grain in a piece of wood, the tubules can move fluids and the cells that live within the tubules respond by sensing the change and transmitting pain sensation