title: [Buffering effects of plaque solid, Streptococcus mutans and glucans].
abstract: OBJECTIVE
  To investigate the buffer capacity of insoluble plaque mass including bacteria and glucans matrix.
  
  
  METHODS
  Plaque samples (starved or incubated 1 h with 10% sucrose), Streptococcus mutans (S. mutans) mass, and insoluble/soluble glucans were titrated with 1 mmol/L HCl. Meanwhile, the density of bacteria was counted and related to buffer capacity.
  
  
  RESULTS
  The bacteria density had significant effects on acid buffer capacity in dental plaque, but the effect reduced with consuming sugar. S. mutans mass with no sucrose incubating contributed to the buffer capacity of (0.609 +/- 0.202) mmol/L, and S. mutans mass with 2% sucrose had only the buffer capacity of (0.099 +/- 0.047) mmol/L. In the mean time, glucans had no effect on acid buffering (0.028 - 0.032 mmol/L).
  
  
  CONCLUSIONS
  The bacteria including S. mutans may be the main contributor to acid buffering in plaque solid.
authors.affiliation: Department of Operative Dentistry and Endodontics, Peking University School and Hospital of Stomatology, Beijing 100081, China. kqlinyue@bjmu.edu.cn
authors.forename: Lin
authors.initials: L
authors.lastname: Yue
authors.forename: Xu-dong
authors.initials: XD
authors.lastname: Bao
authors.forename: Xue-jun
authors.initials: XJ
authors.lastname: Gao
mesh_terms: D000143:Acids; D000293:Adolescent; D000328:Adult; D015169:Colony Count, Microbial; D003733:Dental Caries Susceptibility; D003773:Dental Plaque / Q000382:microbiology / Q000503:physiopathology*; D005260:Female; D005936:Glucans / Q000378:metabolism*; D006801:Humans; D008297:Male; D013295:Streptococcus mutans / Q000378:metabolism*; D055815:Young Adult
chemical_list: D000143:Acids; D005936:Glucans