When new toothpastes are developed, the existing recipes are changed. These need to be tested before manufacturing and production. To keep teeth healthy, they should be brushed twice a day. New toothpastes are always being developed. New recipes may reduce plaque, taste different or feel different in terms of the amount of foam the toothpaste makes. Each property which is changed requires a different kind of test. Sometimes computers help to measure the results, but humans are needed to trial the taste. Machines can be used to scientifically measure the foaming properties of the formula and to carry out fair tests. Markets in different countries have different preferences. Chinese markets like their toothpaste to produce a lot of bubbles, while the German market prefers less foam.
After watching the clip, ask: "Which toothpaste do you use?" The children could conduct a survey of all the different brands used by the class. Pupils could brush their teeth with three sample brands and give their verdicts, scoring the taste of each one out of five. Compile the results into a class graph. The children would also enjoy carrying out the foaming test shown in the clip, using a blender to investigate their three toothpaste brands. They should follow the same procedure they see in the clip. When they have the results of their test, ask: "Which of these brands would do best in China, where shoppers like their toothpaste very foamy?"