It is an early carious lesion. The white lesion is the demineralized enamel and if untreated it can lead to deterioration of tooth. White spots on the teeth can appear after changes have occurred in the mineral content of a person’s teeth (which often happens childhood and leads to eventual deterioration of enamel if left untreated). White spots can also appear in connection with a condition called fluorosis, which is the result of having an excessive intake of fluoride.