Q1 - Dentist: I recommend brushing...

[ohthatpatrick]

Question Type:
Explain Discrepancy

Stimulus Breakdown:
Fact 1: Brush after every meal to get rid of sugars (which lead to bact -> acid -> cavities)
Fact 2: When you can't brush, chew gum, even if the gum has sugar, to help avert cavities.

Answer Anticipation:
GIVEN THAT the dentist wants us to get rid of sugars because sugars can lead ultimately to cavities,
WHY IS SHE SAYING THAT chewing gum w/ sugar in it could help prevent the formation of cavities? Presumably, whatever cavity protection we gain by chewing gum outweighs whatever increase in cavity formation is caused by the minimal sugar in the gum.

Correct Answer:
C

Answer Choice Analysis:
(A) This could almost work. Since gum has so little sugar, the impact that sugar would have on cavity formation is probably negligible. However, we still don't have any reason for why the dentist is recommending a small amount of sugar.

(B) This doesn't tell us why sugar is bad in one case but okay in another. And it tells us nothing about the virtue of gum.

(C) This tells us why chewing gum is good, but why is the sugar okay? Well, it helps that the way in which chewing gum is good is specifically undoing the way in which sugar was bad. Sugar was potentially giving us more bacteria, which gives us more acid, de-mineralizing enamel, and thus leading to cavities. Since gum apparently has the effect of reducing acid and remineralizing enamel, we can tell that (despite having sugar), it's a net gain.

(D) But why chew gum?

(E) Because this doesn't combat the negative effects of sugar, this answer doesn't help us understand how the dentist is at peace with sugared-gum.

Takeaway/Pattern: I think (A) is a tricky answer, because I'd like to know why "gum is good" and why "sugar in gum isn't bad". (A) seems to give the latter. (C) seems to give the former. How do we pick? Ultimately, (C) gives us the latter as well because the positive effects of gum outweigh the negative effects of sugar.

#officialexplanation

[frank0478]

Why is it that dentist recommend chewing gum with sugar
Even though he also recommends brushing teeth after meal to remove the sugar?

There is a disadvantage to leaving the sugar and chewing gum can do more even though the gum itself has sugar? There must be some advantage to chewing gum. In fact, the advantage of chewing gum outweighs the harm that little sugar does.

A. Gum has less sugar than average meal. But we don’t know the advantage of having chewing gum. The dentist wouldn’t say eat small amount of sugar!
B. Discusses too decay, but not why we should chew gum even though it was sugar
C. Discusses the benefit of chewing gum in that it helps re-mineralize tooth enamel
D. Discusses how long sugar can last, but doesn’t resolve
E. Discusses the benefit of chewing gum, but this is relative to overall health which is way too broad

[maryadkins]

Great explanation! Thank you. (C) is correct. We are looking for an answer choice that not only explains why chewing gum with sugar isn't necessarily bad, but why it is actually GOOD. (C) does this. And as you said, (E) is too broad.