The objective of this chapter is to introduce the fluorosis. Fluorosis is a cosmetic condition that affects the teeth. It’s caused by overexposure to fluoride during the first eight years of life. This is the time when most permanent teeth are being formed. Dental fluorosis is also called as mottling of the tooth enamel, due to excess fluoride during the tooth development. Fluorosis symptoms may range from white tiny specks to dark brown stains and rough, pitted enamel which is difficult to clean. The main causes are inappropriate use of fluoride-containing dental products (toothpaste, mouth rinses) and many times children swallow the fluoridated toothpaste. Other causes include fluoridated drinking water, fruit juices, and soft drinks.