Which of the following is NOT a reason to use an explorer during coronal polishing?

Using an explorer during coronal polishing serves a variety of important functions but does not include the scaling of calculus and tartar. Scaling is a specific procedure that involves the removal of hardened deposits from teeth. Coronal polishing, on the other hand, focuses on smoothing the enamel surface and removing soft deposits like plaque and extrinsic stains with a polishing agent.

The role of an explorer in this context is primarily for assessment and determination rather than for the physical removal of hard substances. For instance, it can help a dental professional determine whether stains are intrinsic or extrinsic, and it can assess whether residual deposits have been adequately removed after brushing or polishing has taken place. Thus, option A correctly identifies an action that does not align with the purpose of using an explorer during the coronal polishing procedure.