Ever wondered if your oral hygiene routine is actually optimal? It may be clear that brushing and flossing are necessary, but what about using mouthwash? In this article we’ll cover the research that demonstrates whether mouthwash is actually necessary for optimal oral health, and the mechanism of how some mouthwashes work to improve oral health and how they affect the oral microbiome.
The oral microbiome is critical to maintaining optimal oral health
The oral microbiome is a community of bacteria, fungi, and viruses that live symbiotically with you in your mouth to keep you healthy (for the most part). While harmful bacteria certainly have a bad reputation for causing gum disease and cavities, most microbes in the oral microbiome are actually important for maintaining your health. Most importantly, oral health is driven by homeostasis in the oral microbiome, where microbes in the oral microbiome are completely in balance, helping to maintain health. Alternatively, oral disease is driven by oral dysbiosis, a condition where the oral microbiome is imbalanced, and an overabundance of pathogenic microbes can ruin the ecosystem.
For example, microbes in the oral cavity have been shown to tune the immune system, and prevent progression of periodontal disease. Additionally, they’ve been found to help balance the pH of saliva and remineralize teeth. Recent research has even demonstrated the critical importance of oral microbes in creating nitric oxide, a bioactive molecule responsible for maintaining blood pressure.
In short, not all bacteria in the mouth are bad! Some mouthwashes indiscriminately kill all bacteria, which may actually do more harm than good for your health. However, mouthwash can also be extremely useful in specific circumstances. Mouthrinses and tongue scraping have been shown to be extremely useful to improve the efficacy of oral probiotics, which can boost commensal bacteria.
Positive effects of mouthwash on the oral microbiome
Mouthwash can be a powerful tool to reduce progression and incidence of gum disease and halitosis. However, it is most efficacious for people with existing oral issues such as oral disease and oral microbiome dysbiosis, and should generally be avoided for long-term use.
Negative effects of mouthwash on the oral microbiome
Long-term routine use of alcohol-based or antimicrobial mouthwash is associated with increased risk of hypertension. However, short-term use of mouthwash can be effective at reducing symptoms of disease. For example, short-term use of mouthwash containing CPC has been found to be an effective solution to reduce symptoms of gingivitis or periodontal disease.
Early research also suggests that extended use of CHX and CPC induce negative changes to the oral microbiome. Several studies have now shown that use of CHX leads to decreased diversity in the oral microbiome, and a reduction in the amount of nitrate-reducing species that are critical for producing nitric oxide.
In summary, avoid long-term use of alcohol-based mouthwash or mouthwash with general broad spectrum antimicrobials, such as chlorhexidine (CHX), as these have been associated with hypertension. By contrast, for short-term use, mouthwash containing cetylpyridinium chloride (CPC) has been shown to be effective at reducing symptoms of gum disease, but its long-term effects on the microbiome are still poorly understood.
When to use mouthwash
Research shows that mouthwash is most effective for people with high risk for oral disease, such as halitosis, gum disease, tooth decay, and oral thrush. These issues are most commonly caused by oral microbiome dysbiosis.
Best ingredients in mouthwash
Fortunately, we’ve written all about the best ingredients for mouthwash, which you can find at our blog here.
In short, the best mouthwash for you depends on your oral health and your oral microbiome. Some mouthwashes have ingredients that help specifically with gingivitis, halitosis, while others are more beneficial for tooth decay or oral thrush. For example, mouthwash containing xylitol can help reduce acid production by cavities causing bacteria. In contrast, mouthwash with chlorine dioxide is most effective for people with high abundance of bacteria that cause bad breath and halitosis.
Mouthwash is not necessary for optimal oral health, but can help improve or reset the oral microbiome and oral health of people with oral dysbiosis.