What is one reason why it may be unsafe to perform coronal polishing?

Coronal polishing is a procedure designed to remove extrinsic stains and biofilm from the coronal surfaces of teeth, enhancing both oral hygiene and aesthetics. Choosing to perform coronal polishing when no visible stains are present may be unsafe because it can lead to unnecessary abrasion of the enamel and dentin. This could result in enamel thinning and an increase in tooth sensitivity over time as the polished surface is not required.

Each of the other options suggests potential adverse effects that could result from coronal polishing, such as tooth sensitivity and gum irritation, which are important considerations. However, performing the procedure on teeth that do not require it can compromise the integrity of the tooth structure without providing any benefit, highlighting the importance of assessing the need for polishing before proceeding.