Usage Test on a New Cosmetic Product: Mouthwash

The goal of this clinical trial is to learn if a new mouthwash can help soothing oral mucosa in adult patients with sensitive gums. The main questions it aims to answer are: * Does the investigated mouthwash soothe red gum? * Has the mouthwash antibacterial activities? Researchers will compare with a marketed mouthwash to see if the observed effect is due to the formula or to the general rinsing effect of any mouthwash. Participants will be asked to use the investigated mouthwash or the comparative mouthwash twice a day for 21 days.