Effectiveness and Safety of a Mouthwash Containing Essential Oil Ingredients

Abstract

The mouthwash, Listerine®, was compounded in 1879 from four essential oils. Later, the oils were replaced by one ingredient per oil with approximately 25% ethanol as a vehicle to keep them in solution. From then on, Listerine® was no longer a medicinal plant product. In 2003, a review by the FDA Subcommittee on Oral Health Care Drug Products for Over-the-Counter Human Use concluded that the product is effective and safe, and a review of studies published in the meantime showed that Listerine® fulfils the consensus criteria for an effective antigingivitis/antiplaque product. However, concerns have been raised about the long-term safety of some of the ingredients, particularly the ethanol content, and in the light of these concerns, the evidence has been re-examined for both the efficacy and safety of Listerine®. In summary, the studies support the claim that Listerine® shows benefit for oral health, but the concerns over its safety remain to be clarified. Until these have been addressed, high risk populations (children, alcohol addicts, patients with genetic deficiencies in ethanol metabolism) should use alcohol-free mouthwashes for the maintenance of oral health.

Effect of Terminalia chebula Extract and Chlorhexidine on Salivary pH and Periodontal Health: 2 Weeks Randomized Control Trial

“…Recent researchers have demonstrated that some herbal extracts, including the essential oil (Botelho et al ., ; Astani et al ., ; Vlachojannis et al ., ), pomegranate extract (DiSilvestro et al ., ), Thymus striatus (Couladis et al ., ), Thymus vulgaris (Giordani et al ., ), Mentha piperita L . (McKay and Blumberg, ), Melaleuca alternifolia , Leptospermum scoparium , Calendula officinalis and Camellia sinensis (Lauten et al ., ), have a positive impact against cariogenic, periodontal, fungal pathogens and viruses.…”

Effect of green tea extract and mouthwash without alcohol on Candida albicans biofilm on acrylic resin

“…The antimicrobial and anti‐inflammatory activities of the essential oils of mint, thyme, eucalyptus and wintergreen or another plant rich in methyl salicylate led to the composition of Listerine ® in 1979, as a surgical disinfectant. At that time, Listerine ® was a saturated solution of boric acid, reinforced with ozoniferous oils . Afterwards, the oils were replaced by 0.092% eucalyptol, 0.064% thyme, 0.042% menthol and 0.06% methyl salicylate dissolved in an aqueous ethanol solution (21.6–26.9%) .…”

“…In 2003, the FDA concluded that the traditional product was effective and safe. Nevertheless, concerns have been reported about the long‐term safety, due to the presence of ethanol …”

“…10 Afterwards, the oils were replaced by 0.092% eucalyptol, 0.064% thyme, 0.042% menthol and 0.06% methyl salicylate dissolved in an aqueous ethanol solution (21.6-26.9%). 10 In 2003, the FDA concluded that the traditional product was effective and safe. Nevertheless, concerns have been reported about the long-term safety, due to the presence of ethanol.…”

“…Nevertheless, concerns have been reported about the long-term safety, due to the presence of ethanol. 10 Acetaldehyde, a genotoxic metabolite of ethanol, contributes to the carcinogenicity of alcoholic beverages. Mouthwashes with alcohol lead to salivary acetaldehyde concentrations similar to those found after the consumption of alcoholic beverages.…”