Method 1. Ten teeth of the same sizetype were chosen out of sterilised samples requested from dentists.
2. A tube of toothpaste was chosen.
3. Five clearly labelled beakers were filled with the same volume of five different drinks.
4. The first two teeth were massed with an accurate balance and then brushed with the toothpaste wet with distilled water, one at a time, using an electric toothbrush and a stopclock.
5. The teeth were placed into the first beaker of drink.
6. The next two teeth were massed and then brushed with the same toothpaste and placed in the next type of drink.
7. This process was continued until there were two teeth in each of the five drinks.
The experiment was repeated for the same amount of four other types of toothpaste. The teeth soaked over the half-term holiday, then were massed again.
Teacher: Smita Bora. Size of group: 12. Age: 14 and 15-year-olds.