The effect of sodium lauryl sulfate on recurrent aphthous stomatitis

Abstract

Sodium lauryl sulfate (SLS) is an anionic detergent that has been used as the major or sole surfactant in most dentifrices. But it is local irritating factor to oral mucosa and result in many side effects. This study was to compare the effects of SLS-free dentifrice with that of SLS-containing dentifrice on recurrent aphthous stomatitis (RAS) and figure out the effect of SLS on incidence of RAS.The ninety volunteers were divided into three groups by random and they used two dentifrices among a commercially available SLS-free dentifrice (SLS-free), a commercially available SLS-free dentifrice containing 1.5% SLS (SLS-A), and a commercially available 1.5% SLS-containing dentifrice (SLS-B). They used each dentifrice for 8 weeks and there was a 2-week washout period during which the subject used the same dentifrice as they used before this study. We compared with clinical parameters – the number of ulcers, the number of episodes, the duration of ulcers, mean pain score at tooth bushing, the feeling of dry mouth after tooth brushing, and the change of sensitivity to sour taste – between two phases in each group.The duration of ulcers, and mean pain score were significantly decreased during the period using SLS-free compared to the period using SLS-A. And in infrequent group which defined as the number of days to experience ulcers was 15 and under during the period using SLS-free, the number of ulcers, the number of episodes, the duration of ulcers, and mean pain score significantly decreased during the period using SLS-free compared to the period using SLS-A. The number of episodes, the duration of ulcers, and mean pain score were significantly decreased during the period using SLS-free compared to the period using SLS-B. The number of ulcers, the number of episodes, the duration of ulcers, and mean pain score were decreased during the period using SLS-A compared to the period using SLS-B, but there was no significant difference in all parameters. Subjects felt less dry mouth after tooth brushing when they used SLS-free. Subjects reported that they were more sensitive to sour taste right after using SLS-A or SLS-B than SLS-free. It is not sure that SLS is initiating factor of RAS, but we found out that the number of ulcers, the number of episodes, and the duration of ulcers were increased during the period using SLS-containing dentifrice. Therefore, SLS is thought to be perpetuating factor of RAS.