In biology, quorum sensing (or quorum signalling) is the ability to detect and respond to cell population density by gene regulation. As one example, quorum sensing (QS) enables bacteria to restrict the expression of specific genes to the high cell densities at which the resulting phenotypes will be most beneficial. Excellent tooth whitening effect without hydrogen peroxide: Phytoncide Toothpaste uses a new method to increase pigment absorption without using hydrogen peroxide. Pigments from coffee, soda, etc. attached to the gap of the teeth are absorbed and removed, which returns the brightness of the teeth to you. Hydrogen peroxide is mainly used as a bleach and bleaching agent. It is dangerous to use it to whiten your teeth, as it causes tooth decay and irritation of the gums. Natural edible ingredients used in coffee whipped cream are used.