Self-study
Dentist: I recommend brushing one's teeth after every meal to remove sugars that facilitate the growth of certain bacteria; these bacteria produce acid that dissolves minerals in tooth enamel, resulting in cavities. ███ ████ ████████ ██ ███ ██████████ █ █████████ ███████ ██████████ ███ ████ ████████ ██████████ ███████ ███ █████████ ██ █████████
"Surprising" Phenomenon
Why would chewing sugary gum after a meal help to prevent cavities when sugar is known to lead to the formation of cavities?
Objective
The right answer will be a hypothesis that explains why chewing gum after a meal helps to prevent the formation of cavities. That explanation must offer some dental hygiene benefit of chewing gum that has the potential to outweigh any damage that could be caused by the sugar in some gums.
1.
Which one of the following, ██ █████ █████ ████ ████ ██ █████████ ███ █████████ ██████████ ███████████ ████████████████
a
A piece of ███████ ███ ████ ████████ █████ ████████ ███ ████ █████ ████ ████ ███ ███████ █████
We would expect this to be true—think of how small a piece of gum is! This answer doesn’t explain why chewing gum helps to prevent cavities, though, so it doesn’t reconcile the paradox in the stimulus.
b
Tooth decay can ██ ███████ ███ ████████ ██ ██ ██ ██████ ██████ █ ██████ █████████
While this might be relieving to hear on a personal level, it doesn’t help to reconcile the paradox at hand. We need information about how chewing gum after meals helps to prevent cavities, and this answer choice doesn’t give us that.
c
Chewing gum stimulates ███ ██████████ ██ ███████ █████ ███████ ███████ ██ ███ █████ ███ █████ ████████████ █████ ███████
This is helpful! Sugar leads to cavities because it causes enamel to dissolve, but chewing gum protects enamel. It makes sense, then, that chewing gum after meals helps to prevent cavities even if the gum contains some sugar.
d
Sugars can be ██ █████ ███ ██ ████ ██ ██ █████ ██████ ███ ██████████████ ████████ █████ ██████ ████ ██████████ █████ ██ ████████████
This answer choice has nothing to do with the cavity-prevention benefits of chewing gum after meals, which is what we need the answer to explain!
e
Chewing gum exercises ███ ███████ ███ ███ ███████ ███ ██ ███████████ ██ ███ ███████ ██████ ██ ███ ████ ██████
This answer doesn’t help because it has nothing to do with the impact that chewing gum has on cavity formation. The “overall health of the oral tract” could refer to factors other than cavities.