Written by Henry Lin | Edited by Olivia Cooper
Image by Ann Zzz
When plaque on the surface of teeth is undisturbed, it can eventually spread beneath the gum line and introduce pathogenic bacteria into gum tissues. There, the bacteria produce toxins that your immune system reacts to by causing inflammation in your gums—typically call this gingivitis [1]. Gingivitis involves swollen, receding, easily bleeding gums; if left untreated, it can lead to periodontitis, which is permanent damage of the tissue connecting the teeth to the jawbone; it can cause tooth loss [1]. Preserving your teeth and oral health in general should be a high priority, since it is often indicative of your physical, social, emotional, and mental well-being [2]. But beyond brushing teeth and flossing, mouthwashes are also available; but is a mouthwash necessary, or even beneficial after all the hard work done by the floss and brush? , .
Brushing teeth and flossing are two of the first things that come to mind in terms of protecting teeth, but whether mouthwashes can offer further protection against plaque development is still under study. The fluoride contained in most toothpaste disrupts the function of oral bacteria and creates a less acidic environment, hindering plaque growth [3]. While reports disagree on whether rinsing one’s mouth with water or not after brushing teeth reduces the toothpaste’s effectiveness at blocking plaque formation, most reports seem to agree that post-brush rinsing with a mouthwash—specifically those containing more than 100 milligrams of fluoride per liter—will not dilute existing fluoride concentrations and may even be beneficial [3]. However, many mouthwashes contain ethanol, which metabolizes into acetaldehyde, a likely carcinogen associated with many types of oral cancers [4]. However, a qualitative analysis of eight separate studies has failed to conclusively determine a direct relationship between mouthwash use and risk of oral cancer. So far, mouthwash has only been observed to very temporarily elevate acetaldehyde levels. It is difficult to attribute that to a significant increase in cancer risk [4]. The results support the hypothesis that using mouthwash does not negatively impact the effects of tooth brushing, nor does it pose any inherent risk towards cancer alone. However, researchers have found that using alcohol-based mouthwash while engaging with risk factors like smoking and drinking may contribute additional carcinogens [4].
When combined with tooth brushing and flossing, mouthwashes increase protection against gum disease because it can clean out nooks and crannies in the mouth that tooth brushing or flossing alone may not be able to reach. Overall, it cleans the oral cavity more comprehensively [5]. One study showed that the use of a fluoride mouthwash containing 0.075% cetylpyridinium chloride—a chemical that disrupts bacterial cell membranes—after tooth brushing for four weeks resulted in an average of an 86.8% reduction in oral plaque bacteria, a 14.3% reduction in gingivitis, and an 11.2% reduction in plaque compared to those who simply brushed twice daily [6]. In a systematic review of 8 separate studies, the use of a mouthwash containing either chlorhexidine or essential oils was also shown to significantly reduce gingivitis. Listerine, a mouthwash containing essential oils, was able to reduce inflammation related to gingivitis by 21% on average among individuals [5].
Current studies seem to indicate that post-rinsing with mouthwash does not negatively impact the effects of tooth brushing, and there seems to be no conclusive association between the use of alcohol-based mouthwashes and an increased risk of oral cancer. Given the ability of mouthwash to significantly reduce oral plaque bacteria concentration and inflammation associated with gingivitis, rinsing with a mouthwash after tooth brushing stands as a valid method of preserving oral health.
References: