Sodium lauryl sulfate, also known as sodium dodecyl sulfate, SLS, or sodium laurilsulfate, is a common ingredient in toothpaste and as a surfactant it is basically a type of ‘soap.’ You might be wondering why your toothpaste needs ‘soap’ in it, but it is there to help thicken your toothpaste as well as help it foam up and dissolve dental plaque while you are brushing. It is also cheap and makes formulating various types of toothpastes easy for manufacturers.
However, despite the positives for toothpaste manufacturing, sodium lauryl sulfate has been known to have some significant downsides that make it a good idea to look for a SLS-free toothpaste to brush with instead.
Problems with Toothpastes Containing Sodium Lauryl Sulfate
Sodium lauryl sulfate limits fluoride bioavailability – Studies have found that increasing amounts of lauryl sulfate decreased the amount of alkali soluble fluoride deposited on the enamel. The concentration in dentifrices (fancy name for toothpastes) usually ranges from 0.5-2.0%. Topical fluoride delivery is the primary goal of toothpaste, so to disrupt this action undermines one of the major benefits of brushing your teeth.
- Sodium lauryl sulfate can increase the incidence of aphthous ulcers – This has been confirmed in a handful of studies and it is suggested that the denaturing effect of SLS on the oral mucin layer, with exposure of the underlying epithelium, induces an increased incidence of recurrent aphthous ulcers. Find our more about aphthous ulcers here.
When it comes down to choosing a toothpaste, it makes the most sense to select one that is sodium lauryl sulfate free to avoid the potential downsides and maximize the oral health benefits of toothpaste. If you are curious as to which toothpaste has the most beneficial properties, consult our post on the best toothpaste.