Final answer:
The infant should receive supplemental fluoride at 6 months old, as this is when developing adult teeth can most benefit from it, and it coincides with the eruption of baby teeth. Community water fluoridation is key to preventing tooth decay, and supplements are needed when access to fluoridated water is unavailable.
Step-by-step explanation:
The nurse suggests that the infant receive supplemental fluoride at 6 months old. At this age, according to the Centers for Disease Control and Prevention (CDC), infants benefit from fluoride to help strengthen the adult teeth that are developing under their gums. Additionally, by the age of 6 months, infants have developed the ability to pick up objects and may start putting them into their mouths, increasing the chance for them to benefit from fluoride's protective effect against tooth decay. It's also the age when baby teeth start to come in, making it a key time for fluoride supplementation to support dental health, especially in areas where the water is not fluoridated.
While community water fluoridation is a cost-effective method for preventing tooth decay and is set to reach a national goal with 80% of Americans having access to fluoridated water, those without access may require supplements to receive these oral health benefits. However, it is important to consider the appropriate amount, as excess fluoride can lead to negative health issues such as skeletal fluorosis. The US Environmental Protection Agency sets a maximum level of 4 ppm (4 mg/L) of fluoride in drinking water to prevent such conditions.