title: Antimicrobial effects of essential oils in combination with chlorhexidine digluconate.
abstract: The aim of the present study was to compare antimicrobial effects of essential oils alone and in combination with chlorhexidine digluconate against planktonic and biofilm cultures of Streptococcus mutans and Lactobacillus plantarum. The essential oils included cinnamon, tea-tree (Melaleuca alternifola), manuka (Leptospermum scoparium), Leptospermum morrisonii, arnica, eucalyptus, grapefruit, the essential oil mouthrinse Cool Mint Listerine and two of its components, menthol and thymol. Cinnamon exhibited the greatest antimicrobial potency (1.25-2.5 mg/ml). Manuka, L. morrisonii, tea-tree oils, and thymol also showed antimicrobial potency but to a lesser extent. The combination effect of the essential oil-chlorhexidine was greater against biofilm cultures of both S. mutans and L. plantarum than against planktonic cultures. The amount of chlorhexidine required to achieve an equivalent growth inhibition against the biofilm cultures was reduced 4-10-fold in combination with cinnamon, manuka, L. morrisonii, thymol, and Listerine. We conclude that there may be a role for essential oils in the development of novel anticaries treatments.
authors.affiliation: Dental Research Group, Department of Pathology and Molecular Medicine, Wellington School of Medicine and Health Sciences, University of Otago, New Zealand.
authors.forename: S K
authors.initials: SK
authors.lastname: Filoche
authors.forename: K
authors.initials: K
authors.lastname: Soma
authors.forename: C H
authors.initials: CH
authors.lastname: Sissons
mesh_terms: D000891:Anti-Infective Agents, Local / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects*; D002710:Chlorhexidine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D004338:Drug Combinations; D048191:Lactiplantibacillus plantarum / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D009067:Mouthwashes / Q000494:pharmacology; D009822:Oils, Volatile / Q000494:pharmacology*; D010938:Plant Oils / Q000494:pharmacology*; D012459:Salicylates / Q000494:pharmacology; D013295:Streptococcus mutans / Q000187:drug effects*; D013729:Terpenes / Q000494:pharmacology
chemical_list: D000891:Anti-Infective Agents, Local; D004338:Drug Combinations; D009067:Mouthwashes; D009822:Oils, Volatile; D010938:Plant Oils; D012459:Salicylates; D013729:Terpenes; C057473:Listerine; C010882:chlorhexidine gluconate; D002710:Chlorhexidine