Controlled clinical trials of chlorhexidine for the treatment of gingivitis and periodontitis were eligible for inclusion. Studies were required to report clinical outcomes. The authors excluded studies of chlorhexidine mouth rinse or gel, studies that used preventative interventions in addition to chlorhexidine (for example, fluoride varnishes), studies that reported only bacterial or biochemical outcomes and studies with small sample sizes (not further defined).
Patient populations in the review varied widely and included adolescents, young adults (some intellectually disabled) and older adults with either gingivitis or chronic periodontitis. The age range was 10 to 93 years. The studies used a wide variety of chlorhexidine varnishes, with chlorhexidine concentration ranging from 1 per cent to 40 per cent. In most studies the varnish was applied on a single occasion, but in some cases applications were repeated. For treatment of periodontitis the varnish was used as an adjunct to scaling and root planing. Controls received no varnish or placebo. Outcomes reported in the review were periodontal pocket depth, indices of plaque, bleeding and gingival health (for example, the Loe and Silness gingival index) and microbiological measures. In most studies outcomes were assessed on two to four occasions. Duration of follow up varied from six weeks to nine months.
The authors stated neither how the papers were selected for the review nor how many reviewers performed the selection