Periodontal disease 牙石( calculus): supragingival calculus ●唾石( salivary calculus) subgingival calculus ●血石( serumal calculus) 成份:无机物: 有机物:蛋白一多糖复合物 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 13 牙石(calculus): supragingival calculus 唾石(salivary calculus) subgingival calculus 血石(serumal calculus) 成份:无机物: 有机物:蛋白—多糖复合物 Periodontal Disease