What is one effect that oral hygiene does not contribute to?

Oral hygiene primarily plays a significant role in promoting overall dental and oral health. Regular practices, such as brushing and flossing, are essential for the removal of food particles and plaque, which helps prevent mouth odors, reduces the risk of infections by controlling bacteria, and increases comfort by maintaining healthy gums and teeth.

The aspect referred to in the correct answer is that oral hygiene does not coat and dry the mouth. In fact, proper oral hygiene typically helps maintain a moist environment in the mouth by stimulating saliva production and removing debris. An unhygienic mouth may lead to dryness, since proper care prevents conditions that contribute to dry mouth, like tooth decay and gum disease. Thus, while the other options highlight the positive effects of good oral hygiene practices, this particular effect does not align with the benefits associated with maintaining a regular oral hygiene routine.