Each participant will brush with one of 6 different formulations of toothpastes either with or without water rinsing post-brushing. Participants will randomly be assigned to groups using an online random team generator. Saliva will be collected six times once before brushing and at 1, 15, 30, 60 and 90 minutes post-brushing. Samples will be analysed using fluoride ion-specific sensitive electrode connected to an ion analyser.