When a person spikes the volleyball hard from the other team (or side), a person from the team opposite of the one who just spiked will block the ball and keep it off their si â¦ de.
Tooth decay is the destruction of your tooth enamel, the hard, outer layer of your teeth. It can be a problem for children, teens and adults. Plaque, a sticky film of bacteria, constantly forms on your teeth.
Tooth decay is caused by biofilm (dental plaque) lying on the teeth and maturing to become cariogenic (causing decay). Certain bacteria in the biofilm produce acid in the presence of fermentable carbohydrates such as sucrose, fructose, and glucose.