DEFINITION Gingivitis refers to any inflammation of the gingiva; however, the term is usually used to refer to plaque bacterial-induced gingivitis.
ETIOLOGY AND PATHOGENESIS Plaque bacteria, a susceptible host, and the host’s inflammatory response are all factors in the initiation and development of gingivitis. Bacterial plaque accumulates on the tooth surface and directly, as well as indirectly, stimulates a host inflammatory response. Supragingival plaque initially forms, and if not removed within a few days, it will initiate an inflammatory response within the marginal gingiva (marginal gingivitis). Bacterial plaque forms a biofilm that adheres tenaciously to the tooth surface providing protection against antimicrobial agents. Undisturbed supragingival plaque bacteria continues to mature and will extend subgingivally. Supragingival plaque is primarily a gram-positive aerobic bacterial population, whereas subgingival plaque bacteria are a more prominent population of gram-negative and anaerobic bacteria1. If subgingival plaque persists, it can lead to chronic gingivitis and the potential development of periodontitis.