Relationships between medication intake, complaints of dry mouth, salivary flow rate and composition, and the rate of tooth demineralization in situ

Arch Oral Biol. 2001 May;46(5):413-23. doi: 10.1016/s0003-9969(01)00003-6.


The aim of this study was to describe the relationships between the rate of tooth demineralisation and medication intake, subjective feeling of dry mouth, saliva flow, saliva composition and the salivary level of lactobacilli. The study group consisted of 28 subjects that were divided into three groups according to their unstimulated whole saliva flow rate. Group 1 had an unstimulated saliva low rate < or =0.16 ml/min (n=10), group 2 had one from 0.17--0.30 ml/min (n=9), and group 3 had one >0.30 ml/min (n=9). The rate of tooth demineralization was determined as mineral loss assessed by quantitative microradiography of human root surfaces, exposed to the oral environment for 62 days in situ. The unstimulated and stimulated saliva flow rates, pH, bicarbonate, calcium, phosphate, and protein concentrations, as well as the degree of saturation of saliva with hydroxyapatite and the saliva buffer capacity were determined. The results showed that almost all subjects developed demineralization, albeit at highly varying rates. Eighty-five percent of the subjects in group 1, 33% of the subjects in group 2, and 0% of the subjects in group 3 developed mineral loss above the mean mineral loss for all the root surfaces in this experiment. Futhermore, group 1 differed significantly from groups 2 and 3 in having a higher medication intake, a more pronounced feeling of dry mouth, lower stimulated saliva flow rate, lower stimulated bicarbonate concentration, lower unstimulated and stimulated compositional outputs (bicarbonate, calcium, phosphate, and protein), and a higher Lactobacillus level. The best explanatory variable for high mineral loss in this study was a low unstimulated saliva flow rate. In conclusion, our results suggest that an unstimulated salivary flow rate < or =0.16 ml/min as described by Navazesh et al. (1992), is a better indicator of increased caries risk due to impaired salivation, than the currently accepted definition of hyposalivation (unstimulated saliva flow rate < or =0.10 ml/min), which relates to the function of the salivary glands (Sreebny, 1992).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Analysis of Variance
  • Antidepressive Agents / adverse effects
  • Antihypertensive Agents / adverse effects
  • Aspirin / adverse effects
  • Buffers
  • Durapatite / analysis
  • Estrogens / adverse effects
  • Female
  • Humans
  • Hydrogen-Ion Concentration
  • Lactobacillus / isolation & purification
  • Male
  • Middle Aged
  • Regression Analysis
  • Risk Assessment
  • Root Caries / etiology*
  • Saliva / chemistry
  • Saliva / metabolism*
  • Saliva / microbiology
  • Salivary Proteins and Peptides / analysis
  • Secretory Rate / drug effects
  • Statistics, Nonparametric
  • Tooth Demineralization / etiology*
  • Xerostomia / chemically induced*
  • Xerostomia / complications*
  • Xerostomia / psychology


  • Antidepressive Agents
  • Antihypertensive Agents
  • Buffers
  • Estrogens
  • Salivary Proteins and Peptides
  • Durapatite
  • Aspirin