This paper is a review of current literature combined with clinical observations. Well-controlled maintenance care is a key consideration in the long-term prognosis of treated periodontitis patients. Periodic professional tooth cleaning every 3 to 4 months often is recommended. Furthermore, recent studies indicate a potential need for selected retreatment in problem areas, since minute residual accretions may be left behind during active therapy--even with "open" surgery. While efficient plaque control is essential for optimal results during the healing phase of periodontal therapy, periodic prophylaxis may prevent loss of clinical attachment over long periods of time even for patients with less than perfect oral hygiene.