Bonjela cool mint gel is used to relieve the pan and discomfort of common mouth ulcers and cold sores aids healing of sore spots and ulcers due to dentures and braces bonjela cool mint gel is a clear almost colourless gel which is applied to the inside of your mouth or gums it contains choline salicylate a pain killer and anti inflammatory which soothes sore areas in the mouth and an antiseptic called cetalkonium chloride which kills bacteria and helps prevent infection bonjela cool