title: The pH change after HCl titration into resting and stimulated saliva for a buffering capacity test.
abstract: BACKGROUND
  Saliva collection can provide clinical information about individual patients. However, a correlation between ranking buffering capacity using resting and stimulated saliva is still unknown. The aim of this study was to evaluate the pH change after HCl titration into resting and stimulated saliva for a salivary buffering capacity test.
  
  
  METHODS
  Resting and stimulated saliva (by chewing paraffin wax) were collected from 80 patients. After the pH of both saliva samples was measured using a hand-held pH meter, the saliva samples were titrated with 0.1N HCl to evaluate the buffering capacity. Correlations of ranking buffering capacity (high, medium, low) between stimulated saliva and resting saliva with 30 microL HCl titration and between stimulated saliva and resting saliva with 40 microL HCl titration were statistically analysed by Spearman Rank Correlation Test (p < 0.05).
  
  
  RESULTS
  At 50 microL HCl titration, stimulated saliva buffering capacities were ranked into high (above pH 5.5), medium (pH from 5.5 to 4.5) and low (below pH 4.5). At 30-40 microL HCl titration, the resting saliva buffering capacities were ranked into the same categories. Spearman Rank Correlation indicated significant positive coefficients for the stimulated saliva and resting saliva buffering capacity at 30 microL titration and the stimulated saliva and resting saliva at 40 microL titration.
  
  
  CONCLUSIONS
  Stimulated saliva is more resistant to variation in pH change during HCI titration than resting saliva. Stimulated saliva sampling is a good method to determine buffering capacity during a comprehensive oral health assessment.
authors.affiliation: Cariology and Operative Dentistry, Department of Restorative Sciences, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan. moritsuka.ope@tmd.ac.jp
authors.forename: M
authors.initials: M
authors.lastname: Moritsuka
authors.forename: Y
authors.initials: Y
authors.lastname: Kitasako
authors.forename: M F
authors.initials: MF
authors.lastname: Burrow
authors.forename: M
authors.initials: M
authors.lastname: Ikeda
authors.forename: J
authors.initials: J
authors.lastname: Tagami
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002021:Buffers; D006801:Humans; D006851:Hydrochloric Acid / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D008875:Middle Aged; D012463:Saliva / Q000737:chemistry* / Q000187:drug effects; D012472:Salivation; D012636:Secretory Rate; D018709:Statistics, Nonparametric; D017186:Titrimetry / Q000379:methods
chemical_list: D002021:Buffers; D006851:Hydrochloric Acid