Top foods that are high in fluorine include: sea fish, chicken meet, black tea, mineral water, cocoa, nuts, grains What do we need fluorine for? mineralization of bones and teeth – it is significant for the hardness of tooth enamel, bone matrix stability and bone density it is significant for tooth formation in children fluorine presence in saliva or dental plaque prevents tooth decay by preventing the growth of bacteria producing acids from sugars stored in bones especially while they are growing, it increases their hardness and firmness