Question

which constituent is used to prevent teeth decay

Answer 1

Brush yourteeth at least twice a day with a fluoride-containing toothpaste. Preferably, brush after each meal and especially before going to bed. Clean between your teeth daily with dentalfloss or interdental cleaners, such as the Oral-B Interdental Brush.

Answer 2

Hey mate here's your answer

"Fluoride is a naturally occurring element that prevents tooth decay when ingested systemically or applied to teeth."

Fluoride is the main constituent of toothpaste that prevent tooth decay.

hope it will help u.