Used toothpaste with fluoride. Though the fridge was constantly stoked with sugar, fruit juice, bread and bread toppings. Kid of ironic that my Mum is a dietitian who is mobility obese.
Reasearch indicates that fluorided water is better at covering the surface area of your teeth--brushing with toothpaste mostly removes the layer of plaque and allows the active ingredient to work better.
It's actually phenomenal how little dental research has ever reached consumer behavior or dental care.