Crystal Growth During Remineralization

The process by which demineralized crystals grow to become remineralized is quite complicated. During a period of supersaturation, crystal growth is possible as demineralized crystals seed new crystals from solution. But crystal growth is susceptible to poisoning by foreign substances, and hydroxyapatite growth inhibitors present in saliva can interfere with the process. Therefore, newly precipitated crystals are usually very small and contain many defects, such as missing ions, which make it more soluble. Crystals that are predominantly bathed in a large volume of solution saturated with respect to hydroxyapatite will tend to perfect themselves, as they become remineralized. The soluble parts will re-form and crystals will grow to reach their maximum natural size in a process called Ostwald ripening.1,18