The effect of an essential-oils mouthrinse as compared to a vehicle solution on plaque and gingival inflammation: a systematic review and meta-analysis

Objective The purpose of this review was to systematically evaluate the effects of an alcohol vehicle solution (V-Sol) compared with an essential-oils mouthwash (EOMW) and if available with a water-based control (WC) on plaque, gingival inflammation parameters and extrinsic tooth staining. Materials and Methods The PubMed-MEDLINE, Cochrane-CENTRAL and EMBASE databases were searched. Where appropriate, a meta-analysis was performed, and difference of means (DIFFM) as calculated. Results In total, 971 unique papers were found of which five met the eligibility criteria. The DIFFM of the meta-analysis of four 6-month studies showed that the EOMW provided significantly better plaque control (DIFFM = 0.39, P < 0.00001) and gingival inflammation reduction as measured by the Löe and Silness Index (DIFFM = 0.36, P = 0.00001) as compared to the V-Sol. Regarding extrinsic tooth staining, a small but significant difference (DIFFM = −0.08, P = 0.03) was observed. Conclusion Limited data, but with a low risk of bias, were available to assess the potential benefit of the alcohol-containing V-Sol. ‘High’- and ‘moderate’-quality data were available for the analysis of plaque and gingivitis, respectively. Within these limitations, EOMW appears to provide a significant oral health benefit during the 6 months of use. The data retrieved for this review suggest that the essential oils produce an effect on plaque and gingivitis that extends beyond the V-Sol. Furthermore, the V-Sol proved to be no different from a WC