Triclosan, an antibacterial agent, is a common toothpaste ingredient in the United Kingdom. Triclosan or zinc chloride prevent gingivitis and, according to the American Dental Association, helps reduce tartar and bad breath. A 2006 review of clinical research concluded there was evidence for the effectiveness of 0.30% triclosan in reducing plaque and gingivitis. Another Cochrane review in 2013 has found that triclosan achieved a 22% reduction in plaque, and in gingivitis, a 48% reduction in bleeding gums. However, there was insufficient evidence to show a difference in fighting periodontitis and there was no evidence either of any harmful effects associated with the use of triclosan toothpastes for more than 3 years. The evidence relating to plaque and gingivitis was considered to be of moderate quality while for periodontitis was low quality. Recently, triclosan has been removed as an ingredient from well-known toothpaste formulations. This may be attributed to concerns about adverse effects associated with triclosan exposure. Triclosan use in cosmetics has been positively correlated with triclosan levels in human tissues, plasma and breast milk, and is considered to have potential neurotoxic effects. Long-term studies are needed to substantiate these concerns.
Chlorhexidine is another antimicrobial agent used in toothpastes, however it is more commonly added in mouthwash products. Sodium laureth sulfate, a foaming agent, is a common toothpaste ingredient that also possesses some antimicrobial activities. There are also many commercial products available in the market containing different essential oils, herbal ingredients (e.g. chamomile, neem, chitosan, Aloe vera), and natural or plant extracts (e.g. hinokitiol). These ingredients are claimed by the manufacturers to fight plaque, bad breath and prevent gum disease. A 2020 systematic metareview found that herbal toothpastes are as effective as non-herbal toothpastes in reducing dental plaque at shorter period of follow-up (4 weeks). However, this evidence comes from low-quality studies.
The stannous (tin) ion, commonly added to toothpastes as stannous fluoride or stannous chloride, has been shown to have antibacterial effects in the mouth. Research has shown that stannous fluoride-containing toothpaste inhibits extracellular polysaccharide (EPS) production in a multispecies biofilm greater than sodium fluoride-containing toothpaste. This is thought to contribute to a reduction in plaque and gingivitis when using stannous fluoride-containing toothpastes when compared to other toothpastes, and has been evidenced through numerous clinical trials. In addition to its antibacterial properties, stabilised stannous fluoride toothpastes have been shown to protect against dental erosion and dentine hypersensitivity, making it a multifunctional component in toothpaste formulations.
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