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

What type of stain is characterized by a green stain on the facial surface of the upper anterior teeth?

1. Intrinsic stain

2. Extrinsic stain

3. Intrinsic and extrinsic stain

4. Cigarette stain

The correct answer is: Extrinsic stain

The green stain commonly observed on the facial surface of the upper anterior teeth is classified as an extrinsic stain. This type of stain forms on the external surface of the tooth enamel and is typically caused by lifestyle factors, dietary habits, or environmental influences. In this case, the green color is often associated with the presence of chromogenic bacteria or the consumption of certain food or beverage items. Intrinsic stains, on the other hand, originate from within the tooth structure, affecting the dentin and enamel. These stains result from factors such as trauma, exposure to certain medications (like tetracycline), or developmental conditions. Since the green stain is visible on the external surface of the teeth and can be removed with professional dental cleaning, this categorization as an extrinsic stain is appropriate. Cigarette stain is a specific type of extrinsic stain associated with tobacco use, characterized by a different coloration and appearance. Choosing extrinsic as the most fitting descriptor encompasses a broader range of possibilities, leaving out the specificity required to identify cigarette stain.