Methods: Levels of SOD and MDA in gingival tissues of elderly patients, adult patients, and juvenile patients with periodontitis and healthy old people were measured and compared.

• 方法:测定老年牙周炎患者、健康老年人、成人慢性牙周炎患者和青少年牙周炎患者牙龈组织中超氧化物歧化酶(SOD)和丙二醛(MDA)的水平，并进行比较。