American Board of Orthodontics (ABO) Practice Exam

The primary component of salivary buffering in activated saliva is bicarbonate. Bicarbonate ions play a crucial role in maintaining the pH balance in the oral environment. When acids are produced in the mouth, either from dietary sources or metabolic processes, bicarbonate acts to neutralize these acids, thus protecting the teeth and oral tissues from demineralization and erosion.

Saliva contains various solutes, but bicarbonate is particularly significant in enhancing the buffering capacity due to its ability to participate in acid-base reactions. As the pH of saliva decreases (becomes more acidic), bicarbonate can react with hydrogen ions to form carbonic acid, which helps to stabilize the pH level closer to neutral. This buffering action is essential for maintaining oral health and preventing dental caries and other oral diseases.

Other components mentioned, such as proteins, calcium, and magnesium, have their own roles in saliva, such as providing antimicrobial properties, contributing to remineralization, and participating in various physiological processes, but they do not primarily serve the purpose of buffering acidity in the same way bicarbonate does.