The earliest visible change of enamel caries appears as a white opaque spot that forms just adjacent to a contact point.Dentine caries appears brown with formation of cavity.

• 釉质初期龋呈粉白色或棕黄色斑，表面无缺陷，牙本质龋呈深棕色或灰黑色，有深浅不等的龋洞形成。