In view of the relationship between supragingival and subgingival plaque, chemical agents which alter supragingival plaque may also alter subgingival plaque. As a result, a beneficial effect on gingival health may be anticipated. This article reviews the use of chemotherapeutic agents which reduce plaque and gingivitis. Indications for the use of these agents include patients with problems with mechanical plaque control, extensive splinting or fixed prostheses, intraoral fixation, orthodontic appliances, overdenture abutments and implants, and for patients in the immediate post-surgical period. Improvement of wound healing following periodontal surgery may represent one of the most valuable aspects of use of these agents. As mouthrinses, these agents cannot be expected to significantly alter subgingival plaque. However, for this purpose, their use in irrigation devices deserves further study. Since recent reports have suggested benefits of various mouthrinses when used as irrigants as compared to rinses may also reduce the bacterial back-spray associated with ultrasonic devices and high-speed handpieces, and thus provide a protective effect for dental personnel. The practitioner in the United States is encouraged to recommend products accepted by the American Dental Association's Council on Dental Therapeutics in order to insure both safety and efficacy.