title: [The dynamics of pH, free calcium and total proteins in root plaque fluid and their relationships to the cariogenic potential].
abstract: OBJECTIVE
  To enhance knowledge of root caries by analysis of the dynamics of dental plaque fluids on root surface and their relationships with the caries history.
  
  
  METHODS
  The pH, free calcium and total proteins of dental plaque fluids on sound root surfaces were analyzed before and after the sucrose challenge. Subjects were either root caries-free (RCF) or caries-positive (RCP).
  
  
  RESULTS
  After a sucrose challenge, the pH of plaque fluids dropped significantly and the concentration of free calcium increased significantly. There were no statistical differences in pH (RCF group 6.24 +/- 0.74, RCP group 5.96 +/- 0.70) and free calcium [RCF group (0.60 +/- 0.46) mmol/L, RCP group (0.89 +/- 0.54) mmol/L] between RCF and RCP group before sucrose challenge. Following sucrose exposure, pH (5.14 +/- 0.19) and free calcium [(1.73 +/- 0.74) mmol/L] in RCP group were significantly lower than RCP group [(pH 5.28 +/- 0.16), free calcium (2.73 +/- 1.25) mmol/L]. No interrelationship has been found between the amount of total proteins and free calcium. Components (contents, change trend) in root plaque were strongly related to that in coronal plaque.
  
  
  CONCLUSIONS
  The process of root caries may be consistent to coronal caries regarding to the acid production of bacteria after a sucrose challenge. Plaque compositions show a stronger cariogenic potential in RCP group.
authors.affiliation: School of Stomatology, Beijing Medical University, Beijing 100081, China.
authors.forename: L
authors.initials: L
authors.lastname: Feng
authors.forename: X
authors.initials: X
authors.lastname: Gao
mesh_terms: D002118:Calcium / Q000378:metabolism*; D003773:Dental Plaque / Q000150:complications / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D011506:Proteins / Q000378:metabolism*; D017213:Root Caries / Q000209:etiology / Q000378:metabolism; D019228:Tooth Crown / Q000737:chemistry / Q000473:pathology; D014092:Tooth Root / Q000737:chemistry* / Q000473:pathology
chemical_list: D011506:Proteins; D002118:Calcium