Sodium lauryl sulfate is one of the most widely used synthetic detergents in toothpaste. Generally, surface active agents lower the surface tension, penetrate and loosen surface deposits and emulsify or suspend the debris which the dentifrice removes from the tooth. The concentration in dentifrices usually ranges from 0.5-2.0%. It has previously been shown that sodium lauryl sulfate has the potential to initiate hypersensitivity to metal ions. Furthermore, the mucosal permeability will be increased to oil and water soluble compounds. Experiments from this laboratory indicate that sodium lauryl sulfate will interact with the deposition of fluoride on dental enamel. It is furthermore suggested that this interaction may have the potential to decrease the cariostatic effect of fluorides. Clinical studies from Denmark give support to this statement. In conclusion, sodium lauryl sulfate has some side effects, and future work should therefore be concentrated on finding other possible toothpaste detergents without these side effects.