How should a dry cotton roll be removed from a patient's mouth?

Moistening a dry cotton roll before removal is beneficial as it reduces friction and helps to prevent discomfort for the patient. When cotton rolls are dry, they can adhere to the oral mucosa or the gingiva, making their removal uncomfortable. By adding moisture, you can facilitate a smoother extraction, making the process more pleasant for the patient and minimizing the risk of injury to the soft tissues of the mouth.

The other strategies such as gripping firmly with cotton pliers, retracting the lip, or using suction may be useful in some scenarios but do not address the primary issue of dryness that makes removal difficult. Moistening the cotton roll directly addresses this problem and improves patient comfort during the procedure.