At which pH level does enamel demineralisation first begin?

Enamel demineralization begins at a pH level of around 5.5. This is significant because it reflects the pH threshold at which the acids produced by bacteria metabolizing sugars in the mouth start to erode the minerals in tooth enamel. When the pH in the oral environment drops below this critical level, the conditions become favorable for the dissolution of hydroxyapatite, which is the key mineral component of tooth enamel. This process can lead to cavities if not promptly addressed through the remineralization process or proper oral hygiene practices.

Other pH levels listed, such as 2.5, would indicate a highly acidic environment which is typically beyond the threshold for enamel damage and may cause more severe damage to oral tissues. Meanwhile, pH levels of 7.5 and 9.5 are more alkaline, promoting remineralization rather than demineralization. Understanding the pH scale and its implications is vital in dental health, particularly in preventing and managing tooth decay.