The addition of arginine to the oral environment can increase buffering against organic acid insults. This environmental effect is best described as which of the following?

• A. Ammonia production
• B. Hydrogen peroxide production
• C. Acid production
• D. Buffering

Answer: (D)

Buffering describes how the environment resists pH changes when acids are present. When arginine is metabolized by oral bacteria, the arginine deiminase pathway releases ammonia, which neutralizes acids and raises the pH. This environmental shift toward a higher, more stable pH is the essence of buffering, not the production of ammonia itself or the production of acids or hydrogen peroxide. So the addition of arginine enhances buffering, helping defend against organic acid insults in the mouth.