Use before brushing your teeth 2\. For hygienic reasons, Please replace every 3 months 3\. In the first days of use, the tartar remover may cause some nausea in some case, but the feeling will disappear over time 4\. Keep this product out of the reach of children 5\. For stubborn teeth plaque, it works pretty well . But it is not a substitute for dentist who can get rid of all plaque. Only a professional dentist can do that 6\. Meanwhile, good dental hygiene practices is important too! Please take good, preventative care of your teeth by brushing and flossing regularly, every day