Essential oils-containing mouthwashes for gingivitis and plaque: Meta-analyses and meta-regression.

OBJECTIVES: To evaluate the efficacy of EO as adjuncts to mechanical plaque control (MPC) on the reduction of plaque and gingivitis when compared to placebo or cetylpyridium chloride (CPC).

DATA: Randomized controlled trials of at least 6 months of follow-up including systemically healthy individuals with gingivitis were included.

SOURCES: MEDLINE, EMBASE, Lilacs and SCOPUS were searched up to April 2016. From 3045 citations, 16 studies were included. 14 studies assessed the Quigley-Hein Plaque Index (QHI) and 11 studies assessed the Modified Gingival Index (MGI) and were included in meta-analyses and meta-regression.

STUDY SELECTION: The analysis of risk of bias suggested that the quality of the studies ranged from moderate to low. Mean QHI (WMD=-0.86, 95%CI -1.05 to -0.66) and MGI (WMD=-0.52, 95%CI -0.67 to -0.37) were lower for EO+MPC than placebo+MPC. Reductions in plaque and gingivitis were, respectively, 32% and 24% larger for EO+MPC than placebo+MPC. The decreases in QHI (WMD=-0.95, 95%CI -1.26 to -0.63) and in MGI (WMD=-0.34, 95%CI -0.53 to -0.15) observed in the EO+MPC group, compared to placebo+MPC in interproximal areas, were significantly different and in favor to EO+MPC. EO+MPC compared to CPC+MPC resulted in clinically lower levels of plaque and gingivitis. High heterogeneity (I2 >95%) was found and explained (MGI-R2 =63.6%; QHI-R2 =80.1%) by differences between studies in the percentage of males, supervision of the mouthwashes and provision of oral hygiene.

CONCLUSIONS: EO seems to be superior to placebo+MPC and CPC+MPC for reduction of plaque and gingival inflammation in patients with gingivitis. Expected benefits may be clinically relevant and may also reach the interproximal area.

CLINICAL SIGNIFICANCE: Mouthwashes containing essential oils should be considered the first choice for daily use as adjuvants to self-performed mechanical plaque control.