National Board Dental Hygiene Examination (NBDHE) Dental Hygienist Practice Test

Demineralization of root structures begins at a pH range of 4.5 to 5.5. This acidic environment leads to the dissolution of minerals, particularly hydroxyapatite, which is the primary mineral component of dental enamel and dentin. When the pH drops below this threshold, it indicates a more acidic condition that favors the loss of these minerals from the tooth structure.

Demineralization is often influenced by factors such as bacterial activity, which produces acids as metabolic byproducts during the fermentation of fermentable carbohydrates. In dental hygiene, understanding the significant drop in pH is critical for preventing and managing caries, especially in individuals with exposed root surfaces where the cementum and dentin are more vulnerable to acidic challenges compared to enamel.

The other ranges of pH presented in the choices represent conditions where demineralization either does not occur or happens at a slower rate. Therefore, identifying the correct pH range for initial demineralization is essential for dental professionals to implement preventive measures and educate patients effectively on oral health.