Why do the white spots on my front teeth appear whiter in the morning?

This can happen when a person's mouth becomes drier during the night. When teeth become dessicated, white spots in the enamel appear brighter. Its sort of like looking at wet or dry paint. Since the white spots are defects in the enamel matrix mineralization, they are close to the tooth's surface. Teeth have water content and if a patient breaths through their mouth while sleeping, teeth can become drier. During the course of the morning the teeth will rapidly rehydrate and the white spots will tend to fade.

 About the author: Lawrence Spindel DDS is a dentist in New York City, who has has maintained  a general and cosmetic dental practice for over thirty years.