Essential Oil Mouthwash (EOMW) may be Equivalent to Chlorhexidine (CHX) for Long-Term Control of Gingival Inflammation but CHX Appears to Perform Better than EOMW in Plaque Control

Summary Selection Criteria For inclusion in this systematic review, studies had to be randomized clinical trials (RCTs) or controlled trials in healthy human subjects comparing the effects of essential-oil mouthwash (EOMW) with chlorhexidine (CHX) on plaque and calculus accumulation, tooth staining, and gingival inflammation. Included studies could be either short-term (< 4weeks' duration) or long-term (> 4 weeks' duration). Studies were required to include a specific formulation of EOMW (Listerine, Johnson and Johnson). They reportedly selected this standard formula of EOMW because it was representative of essential oil-based mouthwashes and because it has the American Dental Association seal of approval. Conversely, there were no restrictions on the concentration of CHX used in studies. The CHX concentration in studies varied from 0.1% to 0.2%. Studies could include no brushing (de novo model) or brushing in conjunction with EOMW or CHX. The authors identified 390 unique articles from electronic database searches. Twenty-five of these articles were selected for full review. Seven articles were excluded because they did not meet the inclusion criteria. Hand searching the reference list of selected manuscripts resulted in the addition of one article. The final systematic review included 19 articles, with a total of 826 subjects who completed all trials. The systematic review included short-term studies lasting less than 4 weeks and long-term studies of 4 or more weeks' duration. Six of these trials were included in the 7 separate meta-analyses performed, yielding a total of 315 participants. The age of subjects in the trials ranged from 16 to 62 years. The study by Axelsson and Lindhe was included twice in the metaanalysis of plaque index, gingival index, and stain index because CHX was used in 0.1% and 0.2% concentrations. The studies by Haffajee et al and Charles et al were each used in meta-analyses for both plaque index and gingival index. Three separate meta-analyses included assessments for plaque index, whereas 2 involved gingival index and 2 assessed tooth staining index. Key Study Factor The effects of EOMW or CHX used as a monotherapy (alone) or in conjunction with self-performed daily oral hygiene on periodontal health, was measured by assessments for plaque index4–6 or calculus index,7–8 staining index,9–16 gingival bleeding index,17–20 or gingival index.12,17,18 Main Outcome Measure The primary outcomes of this systematic review and meta-analy