Questions: Dental Health

Question 1

What actually causes a cavity to form in a tooth?

• A. Sugar directly dissolves the tooth enamel
• B. Bacteria in the mouth feed on sugar and produce acid, which dissolves the tooth enamel over time
• C. Teeth naturally weaken and break down as you age
• D. Not drinking enough milk weakens tooth structure

Answer: (B)

Cavities are an indirect result of sugar consumption. Sugar itself doesn't damage teeth. Instead, bacteria that live naturally in your mouth feed on the sugars left on your teeth. As they metabolize the sugar, they produce acid as a waste product. This acid gradually dissolves the hard enamel surface of the tooth, creating a cavity. This is why brushing and flossing remove bacteria and food particles -- cutting off the acid production process.

Question 2

Brushing your teeth harder and with more pressure cleans them better and prevents more cavities.

• T. True
• F. False

Answer: False

Brushing too hard can actually damage your teeth and gums. Aggressive brushing wears down tooth enamel (the protective outer layer) and can cause gum recession (gums pulling away from teeth). Effective brushing is about technique and thoroughness, not force: gentle circular motions covering all surfaces for a full two minutes removes plaque without causing damage. A soft-bristled brush is recommended.

Question 3

Why is flossing important when you already brush your teeth twice a day?

Model answer: Tooth surfaces between teeth are too tight for bristles to reach, so brushing alone misses about 40% of tooth surfaces. Floss slides between teeth and along the gumline to remove plaque and food particles from these unreachable areas. Without flossing, bacteria and plaque accumulate between teeth, leading to cavities in those gaps and gum disease along the gumline.

The geometry of teeth explains why brushing alone is insufficient. Teeth have five surfaces: front, back, top, and two sides where they touch neighboring teeth. A brush can effectively clean three of these five surfaces. The two contact surfaces between adjacent teeth require floss. Skipping floss is like washing only three sides of a dish -- the food stuck to the unwashed sides doesn't go away just because the rest is clean.