The best way to keep white teeth is by maintaining good oral hygiene practices, including brushing twice a day with a whitening toothpaste, flossing daily, and visiting the dentist regularly for cleanings. While it's not necessary to brush after every meal, rinsing with water or chewing sugar-free gum can help remove food particles and prevent staining.
Too much fluoride is also harmful, so it’s recommended you brush twice a day along with scraping your tongue and flossing. Reach out to your dentist for more specific queries!