Tooth decay starts when the pH value of the mouth is,

Key Points

• Tooth enamel begins to demineralize when the pH of the mouth drops below 5.5. This is known as the "critical pH" for enamel.
• At a pH lower than 5.5, the acidic environment allows bacteria like Streptococcus mutans and Lactobacillus to thrive, leading to tooth decay.
• The acid is primarily produced by bacteria as they metabolize sugars and carbohydrates present in food.
• Maintaining a pH level above 5.5 in the mouth is important to prevent enamel erosion and subsequent cavity formation.

Additional Information

• pH Scale:
  • The pH scale ranges from 0 to 14, where 0 is highly acidic, 7 is neutral, and 14 is highly alkaline.
  • The normal pH of saliva in a healthy mouth ranges between 6.5 to 7.5, which is slightly acidic to neutral.
• Tooth Enamel:
  • Tooth enamel is the hard, protective outer layer of the teeth. It is primarily composed of hydroxyapatite, a crystalline calcium phosphate.
  • Enamel is highly vulnerable to acidic environments, which can lead to its demineralization.
• Role of Bacteria:
  • Bacteria like Streptococcus mutans play a key role in tooth decay. They metabolize sugars and produce acids as byproducts.
  • The acids lower the pH of the mouth, creating an environment conducive to enamel erosion.
• Preventive Measures:
  • Regular brushing and flossing help remove food particles and plaque, reducing bacterial activity.
  • Using fluoride toothpaste strengthens enamel and helps resist acid attacks.
  • Avoiding sugary foods and drinks minimizes bacterial acid production.
  • Rinsing the mouth with water or mouthwash can help neutralize acid and restore pH balance.