Gingivitis is a non-destructive disease that causes inflammation of the gums. The most common form of gingivitis, and the most common form of periodontal disease overall, is in response to bacterial biofilms (also called plaque) that is attached to tooth surfaces, termed 'plaque-induced gingivitis'. Most forms of gingivitis are plaque-induced.

While some cases of gingivitis never progress to periodontitis, periodontitis is always preceded by gingivitis.

Gingivitis is reversible with good oral hygiene; however, without treatment, gingivitis can progress to periodontitis, in which the inflammation of the gums results in tissue destruction and bone resorption around the teeth. Periodontitis can ultimately lead to tooth loss.

The focus of treatment is to remove plaque. Therapy is aimed at the reduction of oral bacteria and may take the form of regular periodic visits to a dental professional together with adequate oral hygiene home care. Powered toothbrushes work better than manual toothbrushes in reducing the disease. The active ingredients that "reduce plaque and demonstrate effective reduction of gingival inflammation over a period of time" are triclosan, chlorhexidine digluconate, and a combination of thymol, menthol, eucalyptol, and methyl salicylate.

More Info: en.wikipedia.org