National Dental Assisting Examining Board (NDAEB) Practice Exam

What type of stains are classified as exogenous stains?

1. Intrinsic stains

2. Extrinsic stains

3. Both intrinsic and extrinsic stains

4. Neither; they are endogenous

The correct answer is: Extrinsic stains

Exogenous stains are classified as extrinsic stains because they originate from sources outside the tooth structure. These stains can result from various external factors, including dietary choices (like coffee, tea, or wine), tobacco use, and certain medications. Extrinsic stains typically adhere to the surface of the enamel and can often be removed through professional dental cleaning or good oral hygiene practices, unlike intrinsic stains, which are formed within the tooth structure itself and are generally more difficult to treat. The distinction is important in dentistry, as recognizing these stains helps dental professionals determine appropriate treatment plans and preventive measures for their patients. Understanding that exogenous stains are due to external factors highlights the role that lifestyle choices can play in oral health and aesthetics.