Final answer:
Fluoridated water contributes to dental caries prevention both systemically, by strengthening developing teeth from the inside, and topically, by enhancing the remineralization of the tooth surface.
Step-by-step explanation:
The major effect of fluoridated water in the prevention of dental caries is both systemic and topical. Systemically, when fluoridated water is consumed, fluoride can become incorporated into the development of teeth, making the enamel stronger and more resistant to decay. Topically, as part of regular consumption, it provides a consistent and frequent contact with the teeth, aiding the process of remineralization which helps to strengthen the tooth surface, preventing and even reversing early stages of tooth decay.