From the point we first began using fluoride, it has been a major factor in the decline in prevalence and severity of dental (cavities). Dental cavities is the most common disease in children and adults (5x more common than asthma). When used properly systemically (in water) and topically (toothpaste) fluoride is antibacterial and makes your teeth resistant to cavities by making them harder. It is an integral part of oral health care.