Final answer:
Teeth are integral to both the physical and chemical digestion processes in the mouth, where they mechanically break down food and initiate chemical digestion with the help of saliva. Tooth decay can occur due to the chemical actions of acids produced by bacteria metabolizing sugars in the oral cavity.
Step-by-step explanation:
Teeth are part of the physical and chemical digestion processes that begin in the mouth or oral cavity. The mechanical breakdown involves the teeth tearing, grinding, and breaking down food into smaller particles. This physical action is also supplemented by chemical digestion, wherein digestive secretions in the mouth commence the breakdown of complex food molecules into their chemical building blocks.
When discussing tooth decay, it is important to highlight the role of bacteria such as Streptococcus mutans, which metabolize sugars and create acids as byproducts. These acids contribute to tooth decay by dissolving the minerals of the teeth, such as enamel, which is the hardest substance in the body but still vulnerable to chemical erosion.