Which medication is commonly used as an adjunct in periodontal therapy?

Doxycycline is commonly used as an adjunct in periodontal therapy primarily because of its unique anti-collagenase properties. In periodontal disease, the breakdown of connective tissue, including collagen, plays a crucial role in the progression of tissue destruction. Doxycycline, a tetracycline antibiotic, helps inhibit matrix metalloproteinases (MMPs), which are responsible for collagen breakdown. By reducing the activity of these enzymes, doxycycline helps maintain the integrity of the periodontal tissue, aids in the healing process, and enhances the overall effectiveness of periodontal treatments, such as scaling and root planing.

This use of doxycycline goes beyond its antibacterial properties, as controlling the host's inflammatory response is vital in managing periodontal diseases. Other medications listed, while they may have their respective roles in managing pain or bacterial infections, do not have the same documented efficacy in directly supporting periodontal tissue preservation and healing as doxycycline does.