Periodontal disease 着色( (stains) o化学物质和食物 o烟草 o色源细菌 Department of Oral Pathology, Shandong University http://course.sdu.edu.cn/oralhistopath.htmlDepartment of Oral Pathology, Shandong University http://course.sdu.edu.cn/oralhistopath.html 11  着色(stains)： 化学物质和食物 烟草 色源细菌 Periodontal Disease