AskERIC Lesson Plans
Lesson Plan #: AELP-BSS0007

What Causes Tooth Decay

An AskERIC Lesson Plan

Author: Melodie Hill; edited by AskERIC
School or Affiliation: Lewis Arriola Elementary School, Cortez, CO 

Grade Level/Subject: Health: Grades 2-6


Tooth decay is one of the most common diseases today. To help students understandthe causes and implications of tooth decay, this activity uses vinegar andegg shells in a simulation of teeth decomposition.


Students will be able to:

1. Show the parts of a normal tooth. These include enamel, pulp, dentin, crown, neck, and root.
2. Identify the causes of mouth acids (saliva and food particles).
3. Show the effects of weak acids on calcium as an example of weak mouth acids on teeth enamel which contains calcium as a main ingredient.
4. Chart micro-organism growth and decline as the food supply runs out.
5. Describe factors that inhibit micro-organism growth:
          cold, sunshine, sterilization, etc.
6. Describe ways that micro-organisms are used successfully.


Paper plates, one per child, small container or jar, tape, egg shells, crackers,bread, vinegar, graph paper, hand mirrors, worksheet pages, teeth if available.Student materials: Pencil or other writing utensil.


1. Have students eat a cracker and observe it on a paper plate. What happened? Why?
2. Place cracker on paper plate. Add water. What happened? Why?
3. Place another cracker on paper plate. Add vinegar. It should dissolve even more than water showing that saliva contains a weak acid similar to vinegar.
4. Using tape, label a small container (baby food jar) with students name. Place egg shell in jar. Explain that teeth enamel is made of the same stuff (calcium) as egg shell. Pour small amount in vinegar in, enough to cover half of shell.
5. Cap jars and label the date on the lid. Let sit several days. Observe changes every day. Have students draw egg shell enlarged on graph paper.
6. Have students bring in lost teeth of their own. These can also be animal teeth. Show crown, neck and root. Split a tooth if possible to show enamel, pulp and dentin. Use a worksheet to reinforce.
7. After several days blacken in squares on graph paper to show holes in egg shell. Explain that the holes are places where the acids dissolved the calcium. Explain that enamel on outside of teeth is also made of calcium.
8. Using a small hand mirror, have students look at their own teeth. Note areas that appear black or dark. Note fillings or caps on worksheet page. Explain that back teeth (molars) are more at risk because of gum chewing and grinding food.
8. Have students compare teeth charts.

Useful Internet Resources:

Brushing Your Teeth

The American Dental Association

Canadian Dental Association

The American Association of Orthodontists

Ask the Dentist

This activity has been copied, with permission, from the Educational Resources Information Center (ERIC) server to ours, to allow faster access from our website. We encourage you to explore the original site.

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