6th Grade · Science · Activity · shared by Luke Morgan
This 6th Grade Science activity investigates Alex's sudden cavities, exploring dental biology, the mouth microbiome, bacteria, and acid's effect on tooth…
Twelve-year-old Alex has always had a perfect dental record with zero cavities. However, at this morning's six-month checkup, the dentist discovered four new cavities starting to form. Alex's habits seem the same: brushing twice a day and avoiding soda. Something in Alex's environment or routine has shifted, disrupting the mouth's natural defenses and threatening Alex's smile. Your mission is to examine the evidence, analyze the biological competition in the mouth, and identify the cause of this sudden dental crisis.
Phase 1: Evidence Collection
Examine the following four clues collected from Alex's home and daily schedule. Look for connections to how bacteria like S. mutans (the "villain") and S. salivarius (the "protector") behave.
Clue A: The Bathroom Counter
Clue B: The New Nightly Routine
Observation: Alex's toothbrush is damp, and the tube of fluoride toothpaste is nearly empty. A new bottle of "Ultra-Blast Alcohol Mouthwash" sits nearby. The label says: "Kills 99.9% of all bacteria instantly!"
Observation: For the last three months, Alex has been studying late for the Science Bowl. To stay focused, Alex sucks on "Sugar-Free Sour Zaps" candies while reading.
Clue C: The Kitchen Pantry
Clue D: The Microbiome Lab Report
Observation: Alex's parents stopped buying granola bars and replaced them with fresh apples and almonds. Alex eats an apple every day after soccer practice.
Observation: A swab of Alex's mouth shows that plaque levels are low, but the interference from helpful bacteria has dropped significantly. The protective S. salivarius population is nearly gone.
Initial Deduction: Based on the clues above, which piece of evidence suggests that the "protective neighbors" in Alex's mouth are being removed? Explain your thinking.
Phase 2: Scientific Analysis