If you want to prevent tooth decay and bactus, you regularly use a toothbrush.

According to the Stiftung Warentest, however, many toothpastes contain unnecessary and possibly harmful dyes, as the product testers announced on Wednesday.

Of the 31 toothpastes tested, 21 contained titanium dioxide – the coloring agent gives the toothpaste a brilliant white colour, but is suspected of damaging the genome.

Five ten creams scored very well in the product test.

Important when choosing toothpaste: The cream should contain sufficient fluoride, the substance strengthens the enamel and makes it less sensitive to acids.

However, four of the products tested did not contain any fluoride and were therefore rated as unsatisfactory.

Five toothpastes were able to complete the product test with the best rating: They contained fluoride, which is important for preventing tooth decay, and did not contain the coloring agent titanium dioxide.

According to Stiftung Warentest, the cheapest test winners were already available for less than one euro per 100 milliliters.