Fifteen edentulous patients with overdentures supported by two implants in the mandibular canine regions received periodontal therapy using both hand instrumentation with Teflon curettes and a glycine-based airflow system. Periodontal probing depth (PPD), bleeding on probing (BOP), and bacterial content (BC) within the gingival sulcus were analyzed. A significant effect modification of the glycine airflow with respect to time was found for PPD (P = .01), BOP (P .001), and BC (P = .004), which were treated as ordered categorical variables. Glycine airflow may be more effective than Teflon curettes for the maintenance of periimplant soft tissues.