Which procedure involves monitoring bleaching materials after placement by a dentist?

The correct answer highlights the critical responsibility of dental professionals during the process of in-office teeth whitening treatments. Monitoring and removing in-office bleaching materials is essential because it ensures patient safety and the effectiveness of the treatment. This procedure involves placing bleaching agents on the teeth, which then require careful observation to minimize any potential adverse reactions, such as gum irritation or sensitivity.

Additionally, the dental professional is tasked with removing these materials after a set period, preventing prolonged exposure that could lead to complications. This active management differentiates the procedure from other options listed. While taking impressions, cementing crowns, and applying topical fluoride are important tasks in dental hygiene and restorative procedures, they do not specifically involve the continuous monitoring of materials that have been placed in the mouth, highlighting the unique responsibility associated with in-office bleaching.