Dental plaque(匾) is the material that adheres(坚持) to the teeth and consists of bacterial(细菌的) cells (mainly S. mutans变形链球菌 and S. sanguis血链球菌), salivary(唾液的) polymers(聚合物) and bacterial extracellular(细菌细胞外的) products. Plaque is a biofilm(生物膜) on the surfaces of the teeth. This accumulation(积聚) of microorganisms(微生物) subject the teeth and gingival(齿龈的) tissuesto high concentrations(浓度) of bacterial metabolites(代谢物) which results in dental disease. If not taken care of, via brushing or flossing(用牙线洁牙), the plaque can turn into tartar (its hardened(变硬的) form) and lead to gingivitis(齿龈炎) or periodontal(齿根膜的) disease.
牙斑菌主要由细菌细胞（主要：变形链球菌和血链球菌），唾液聚合物，和细菌细胞外物质组成。微生物在牙齿和牙龈表面累积，并产生新陈代谢物质，如果不用牙刷和牙线清除，牙斑就会变硬，导致牙周炎，牙龈炎。
Biofilms are communities of bacterial cells that are attached to a special surface, and cells are embedded in a matrix which is called extracellular polymeric substance.
细菌生物膜是细菌在特定条件下形成的一种特殊细菌群体结构，菌体被包裹在其自身分泌的多聚物中。
原文：http://www.cnblogs.com/biopy/p/4300359.html