What does a cotton roll holder do in a dental setting?

A cotton roll holder is specifically designed to securely hold two cotton rolls in place within a patient's mouth during dental procedures. This instrument serves multiple critical purposes: it helps to dry the area being treated, isolates specific teeth or tissues, and protects the surrounding oral cavity from contamination or moisture. By keeping the cotton rolls in place, the holder allows the dental professional to have both hands free to perform tasks more efficiently, enhancing visibility and access to the working area.

The other options refer to different dental instruments that have distinct functions unrelated to isolation and drying. For instance, holding dental floss is not relevant to the role of a cotton roll holder, as is the function of securing a dental mirror or storing anesthetic cartridges. Each tool in a dental setting has a specific purpose, and understanding these differences is crucial for effective assistance during dental procedures.