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

Which of the following is NOT a major component of saliva that protects against dental caries?

1. Calcium

2. Sodium

3. Iron

4. Phosphate

The correct answer is: Iron

Saliva plays a crucial role in oral health, particularly in the prevention of dental caries, by maintaining a balanced environment in the mouth and providing essential components that enhance remineralization of tooth enamel. Key components of saliva that contribute to its protective effects against dental caries include calcium, phosphate, and bicarbonate, which help neutralize acids and promote the remineralization process. Calcium and phosphate ions in saliva are fundamental in the formation and maintenance of tooth enamel. These ions are necessary for the remineralization of enamel after demineralization caused by acids produced by bacteria. The presence of sodium in saliva, while important for maintaining osmotic balance and other physiological functions, does not have a direct role in caries prevention in the same way that calcium and phosphate do. Iron, on the other hand, is not a significant or direct component of saliva in the context of protecting against dental caries. While iron is an essential nutrient for overall health and plays roles in various biological functions, it does not contribute to the protective mechanisms against dental caries. Therefore, identifying iron as not being a major protective component of saliva aligns with the understanding of saliva's primary protective functions.