Dental Admissions Test (DAT) Practice Test

What is the ideal pH level to prevent tooth decay?

1. 5.0 to 5.5

2. 6.2 to 7.0

3. 7.5 to 8.0

4. 8.5 to 9.0

The correct answer is: 6.2 to 7.0

The ideal pH level to prevent tooth decay is typically in the range of 6.2 to 7.0. This range is crucial because the enamel on our teeth begins to demineralize at a pH of around 5.5. When the pH drops below this level, the acidity can lead to the dissolution of minerals in the enamel, which is what leads to cavities and tooth decay. Maintaining a neutral pH, ideally between 6.2 and 7.0, helps to foster an environment where the saliva can function effectively in remineralizing enamel and neutralizing acids produced by bacteria in the mouth. Saliva plays a key role in maintaining oral health due to its buffering action against acidity, and keeping the pH within this optimal range enhances its protective effects. Choices indicating lower pH levels suggest an environment that is more acid, which can contribute to the risk of decay. Higher pH levels would further reduce acidity but are not necessary for preventing decay, as they may not reflect the ideal balance needed for dental health. Thus, maintaining a pH within the range of 6.2 to 7.0 is considered ideal for preventing tooth decay.