The process of changing from about 30% inorganic mineral in enamel matrix of the teeth to the 96% inorganic content in mature enamel. The maturation is accomplished by the ameloblast cells over a long period, with a decrease in water and organic content, and an increase in mineral content and size or density of hydroxyapatite crystals. The final stages of enamel maturation occur after the tooth has erupted into the oral cavity.