Macroscopic observation : Smooth surface caries is conical in shape with its apex towards the dentine. Fossa, pit or fissure caries is on the contrary.

• 肉眼观察：平滑面龋多呈底向外，尖向内的三角形及其它不典型形态，而窝沟龋的病损呈倒三角形（尖向外，底向内），病变区常有黄色色素沉积。