What is a possible side effect of using chlorhexidine mouthwash?

Chlorhexidine mouthwash is an antimicrobial agent commonly used for managing oral infections and controlling plaque and gingivitis. A well-documented side effect of chlorhexidine is teeth staining. This occurs because chlorhexidine can bind to the surfaces of teeth and other oral tissues, leading to discoloration over time, particularly with prolonged use. This staining is often more noticeable on natural teeth than on dental restorations.

While dry mouth, increased saliva, and gum irritation can occur with various oral products, they are not the primary concern associated with chlorhexidine. Dry mouth is more commonly associated with medications that reduce saliva production, increased saliva is typically not a reported effect of this mouthwash, and gum irritation is not widely recognized as a significant problem specifically attributable to chlorhexidine compared to the well-established issue of tooth staining. Therefore, the most relevant and significant side effect related to chlorhexidine mouthwash is indeed teeth staining.