Abstract: There is provided a smart baby bottle for preventing tooth decay in infants, including a first compartment containing a first liquid (such as milk), a second compartment containing a second liquid (such as water), and an electrical two-way solenoid valve for controlling a flow of the second liquid from the second compartment into the first compartment. The baby bottle also includes a pacifier which can be mounted interchangeably to both compartments as needed. The solenoid valve receives electrical signals from a plurality of electrical sensors. The electrical two-way solenoid valve automatically opens and allows flow of water from the second compartment into the first compartment, when milk contained in the first compartment is completely finished by an infant. Hence, the infant's teeth are rinsed with the water subsequent to milk—thereby reducing tooth decay in infants considering that there will be reduced exposure to liquids containing sugar.