Corsodyl chlorhexidine dental gel helps prevent and treat gum disease it contains the active ingredient chlohexidine which when used daily has been proven to help prevent the formation and build up of plaque on the teeth what is it used for prevents the build up of plaque on the teeth helps maintain oral hygiene prevents and treats gum disease gingivitis prevents tooth decay in people at high risk for example people with a dry mouth due to poorly functioning salivary glands xerostom