Showing photos of cavities — while it sounds extreme — has been reported as immediately effective by multiple parents. The key is not to scare them about dentists or procedures, only about the result of not brushing. Other strategies include electric toothbrushes which toddlers find exciting, letting them choose their own toothbrush, and brushing together as a family. For fluoride toothpaste, Colgate 2-5 years is commonly recommended by paediatricians. If resistance is extreme, make brushing non-negotiable but keep the tone light rather than punitive.