METHODS: Biofilm model to quantify single-species (S.mutans ATCC7 or L. acidophilus ATCC) and dual-species (S.mutans ATC方法:变形链球菌(S.mutans,ATCC 7)和嗜酸乳杆菌(L．acidophilus,ATCC )在9孔板培养8h形成单菌种和双菌种生物膜。