What's really in your mouthwash? Turkish study spills the minty truth

By Neha MathurReviewed by Benedette Cuffari, M.Sc.Sep 17 2023

In a recent study published in the International Dental Journal, researchers analyze the relative proportions and health benefits of mouthwash components available in the oral care aisles of large retail stores and pharmaceutical outlets in Turkey. 

Study: Ingredients in Commercially Available Mouthwashes: A Review. Image Credit: goffkein.pro / Shutterstock.com

Background

Most commercial mouthwash products consist of antibacterial, anti-malodor, and antioxidant components that combat the accumulation of dental plaque, which is the primary cause of dental caries and periodontal disease.

However, some mouthwash ingredients, including parabens, sodium lauryl sulfate, and chlorhexidine (CHX), also have side effects, such as allergic reactions, taste-related disturbances, and altered tooth-coloring. Although some studies claim a link between oral cancer and the use of certain mouthwashes, there remains a lack of epidemiologic evidence supporting these claims.

Previous studies have examined the ingredients of commercially available toothpaste in Turkey; however, to date, none have investigated the constituents of mouthwash products sold commercially in Turkey. 

About the study

The present study, conducted between September 2021 and April 2022, is one of the first to comprehensively examine all components in mouthwash brands commercially available in Turkey. The researchers also described the potentially toxic side effects of each of the unique mouthwash ingredients. 

Various search engines such as Google Scholar, PubMed, and ScienceDirect were screened to determine the role of each unique mouthwash ingredient and its potential side effects on oral and other body tissues. Subsequently, a list of mouthwashes sold in pharmacies in Istanbul was compiled. 

The researchers meticulously collected and organized all mouthwash labels within an archive to help visualize each unique ingredient in mouthwashes. The frequency of occurrence of each mouthwash ingredient was calculated as a percentage. Mouthwash ingredients with similar usage and function were also characterized.

Study findings

The dental/oral health survey conducted in Turkey in 2021 showed that the incidence of dental disorders in the Turkish population was high. More specifically, the prevalence of caries and bleeding gums was 64% and 16.2% in five-year-old children, respectively.

Furthermore, the incidence of gingival bleeding in the 12 and 35-44 age groups was 48.7% and 70.8%, respectively. Notably, the estimated utilization rate of mouthwash in Turkey is 30%, which is much lower as compared to toothpaste.

Overall, 17 brands sold 45 distinct mouthwash products with 116 unique ingredients in Turkey. The most frequently encountered mouthwash ingredients were aroma, sodium fluoride, sodium saccharin, sorbitol, propylene glycol, poloxamer, glycerin, and menthol. 

About 62% of mouthwash products contained sodium fluoride as the active constituent in varying concentrations. While most mouthwashes had 225 parts per million (ppm) or higher concentrations of sodium fluoride, only nine contained less than 225 ppm of sodium fluoride. Notably, the authors could not determine a specific concentration of sodium fluoride in a single gargle.

Although fluoridated mouthwashes remain in the oral cavity for longer durations, rinsing the mouth with water can reduce fluoride retention. Therefore, one should use a combination of fluoride-containing mouthwash and toothpaste to enhance fluoride retention.

These findings raise questions regarding societal awareness of the potential benefits or hazards of fluoride components used in oral care products, including mouthwashes. Thus, future studies are needed to determine fluoride awareness, as excessive ingestion of fluoride compounds could lead to dental and skeletal diseases.

Other active ingredients in mouthwash variants were oxygene, chlorhexidine digluconate (CHX), and zeolite, which were present in three, five, and one products, respectively.

A CHX concentration of less than 0.1% cannot effectively combat dental plaque. However, mouthwashes sold in Turkey consisting of CHX as an active ingredient use CHX concentrations between 0.025-0.2%, thus indicating that these products are not likely to protect against oral diseases.

CHX disrupts the integrity of the bacterial cell membrane to ultimately lead to cell lysis, in addition to inhibiting biofilm formation and maturation. However, several studies have also reported that CHX alters the oral environment, thereby facilitating caries formation that accelerates cardiovascular diseases.

Most mouthwash products sold in Turkey were water or water-alcohol-based. Some mouthwash products included alcohol on their labels; however, whether these products contained ethyl alcohol, which could be a public health concern, was not clear.

Case-control studies claim that alcohol-containing mouthwashes likely increase the risk of oral cancer. Currently, most mouthwash brands using benzyl alcohol adhere to European Union regulations and use less than 1% benzyl alcohol, which is considered a safer ingredient than ethyl alcohol.

In an era where natural components are gaining popularity, many mouthwash products incorporate menthol derived from Mentha arvensis, which has antibacterial, analgesic, and stimulant qualities. However, more clinical studies on herbal mouthwashes containing phytotherapeutic herbs and essential oils are needed.

Conclusions

Research on the detrimental consequences of the overuse of mouthwashes is scarce. Thus, there is an urgent need for future studies to evaluate the human and environmental health impacts of dental care products, including mouthwashes.