Discussing the importance of the supplement, a co-author of three of the articles, Dr Michael McCullough, who is professor of oral medicine at the Melbourne Dental School, told Dental Tribune International (DTI) that the lack of consensus worldwide regarding the use of mouthwash prompted FDI to form a task team to further explore the topic. “This supplement provides an easy-to-read guide on mouthwash use based on the current best available evidence,” he said.

The efficacy of mouthwash use in maintaining oral health is well documented in the literature. However, it often shows varying degrees of evidence. “Mouthwash use decreases plaque and gingivitis in many short-term studies, most of these studies assessing chlorohexidine-containing mouthwashes. However, the evidence for their effectiveness in preventing periodontal disease is not currently available,” Prof. McCullough explained.

Prof. Michael McCullough. (Image: Michael McCullough)

“There is moderate evidence for the adjunctive use of fluoride-containing mouthwashes for the prevention of coronal caries in children and adolescents but not in adults. Further, there is limited evidence of the effective use of mouthwashes to aid healing post surgery, chemotherapy-induced mucositis and the management of alveolar osteitis. Finally, there has been a great deal of interest in the antiviral properties of mouthwash recently, particularly associated with the COVID-19 pandemic. However, more clinical research is needed to show a clear benefit,” he continued.

Besides its potential benefits, mouthwash has been shown to have adverse effects. For example, DTI has previously reported on research that indicates that mouthwash may impede the benefits of exercise and raise blood pressure.

“There is increasing evidence, particularly using modern tools assessing bacterial metagenomics, to suggest that mouthwash use can result in a dysbiosis in oral bacteria as well as potentially lead to antimicrobial resistance. Further, links between mouthwash use and cardiovascular disease, diabetes mellitus, oral cancer, Alzheimer’s disease and pre-eclampsia have been proposed, however with variable and limited levels of evidence,” Prof. McCullough explained.

The supplement also delves into the future directions of mouthwash, including alternatives to conventional mouthwashes. In this regard, DTI has reported on a study that examined the effectiveness of cannabinoid-infused mouthwashes in fighting plaque, comparing them with chlorhexidine mouthwashes.

Discussing the emerging role of mouthwash in dentistry, Prof. McCullough commented: “There are currently several types of mouthwash being developed that may be able to modulate oral immune reactions for the treatment of oral mucositis, as well as nanoparticle-containing mouthwashes that have the potential for more-targeted antimicrobial action. There are also the impacts on the environment of widening mouthwash use with more new products, including increased use of packaging, potential antimicrobial resistance and possible detrimental effects on marine life, that need to be considered.”

“The long-term use of mouthwash has to be recommended with a balance between the known benefits and these potential adverse effects,” he concluded.

Editorial note:

On 16 January at 10 a.m. CET, FDI will be holding a webinar on the role of mouthwash in oral care. More information about the event can be found here.