A fissure is a crack that is associated with the chewing surface of molars. If left untreated, fissures tend to cause tooth decay as bacteria find fissures ideal place to breed. Normally, the toothbrush bristle is too large to clear food residues that reside in the cracks (fissures).  The remedy dentists will use is “fissure sealants” – a chemical that seals the cracks and make them “germ-proof”. The procedure for a fissure sealant is very simple and only takes a couple of minutes. It varies slightly depending on the type of sealant.