单项选择题
A.0.25% B.0.50% C.1% D.2% E.2.50%
A.0.50% B.1% C.1.50% D.2% E.2.50%
A.慢性龈缘炎 B.青春期龈炎 C.早期性牙周炎 D.侵袭性牙周炎 E.VitC缺乏性龈炎