The aim of this study is to evaluate the therapeutic effectiveness of chlorhexidine mouthrinse on gingival inflammation and subgingival microbiota in addition to daily mechanical plaque control in a population with established gingivitis.

Failure to perform oral hygiene adequately at the gingival margin results in the formation of a pathogenic plaque that has the potential to initiate gingivitis and in some individuals to progress to periodontitis. However, factors, such as dexterity and motivation, can limit the effectiveness of daily self-performed oral hygiene. The use of a chemical plaque-inhibitory mouthrinse as an adjunct to toothbrushing may improve the oral health of individuals who are inadequate in mechanical plaque control in maintaining gingival health.

Chlorhexidine (CHX) has been effectively used in the treatment of gingival inflammation and can be considered as the gold standard for oral antiseptics.

The effectiveness of CHX in reducing the formation of dental plaque and preventing gingivitis in addition to professional mechanical debridement were studied in several clinical studies, but there is limited number of studies investigating the effects of CHX on untreated gingivitis and subgingival microbiota.

Inclusion Criteria:

• 18-45 years old male or female with gingivitis associated with dental plaque, no clinical signs of destructive periodontal disease, clinical attachment loss < 3mm, a minimum of 20 teeth (teeth that have gross caries, were fully crowned or extensively restored, orthodontic banded, abutments, or third molars were not included in the tooth count).

Exclusion Criteria:

• use of tobacco products, history or current manifestation of systemic disease which could impair immune response such as diabetes mellitus, immunological disorders, hepatitis and HIV infections, use of antibiotic or anti-inflammatory or immunosuppressive drugs during 3 months period prior to the start of the trial, periodontal therapy during the last 3 month, pregnancy or lactation and oral contraceptives usage.