Address of Corresponding Author

Caries Res 2005;39:521-528 (DOI: 10.1159/000088190)

  Key Words

• Fluoride
• Glycolysis
• Mutans streptococcus
• Xylitol

  Abstract

The purpose of this study was to evaluate the combined inhibitory effect of fluoride and xylitol on acid production by mutans streptococci, Streptococcus mutans NCTC10449 and Streptococcus sobrinus 6715, from glucose under strictly anaerobic conditions at fixed pH 5.5 and 7.0. The bacteria were grown in a tryptone-yeast extract broth under strictly anaerobic conditions (N₂: 80%; H₂: 10%; CO₂: 10%). Reaction mixtures for acid production from glucose contained bacterial cells with fluoride (0-6.4 mM) and/or xylitol (60 mM). Acidic end products of glucose fermentation and intracellular glycolytic intermediates were assayed. The combination of fluoride and xylitol inhibited acid production more effectively than fluoride or xylitol alone. In the presence of fluoride and xylitol, the proportion of lactic acid in the total amount of acidic end products decreased, while the proportion of formic and acetic acids increased. Analyses of intracellular glycolytic intermediates revealed that xylitol inhibited the upper part of the glycolytic pathway, while fluoride inhibited the lower part. This study indicates that fluoride and xylitol together have synergistic inhibitory effects on the acid production of mutans streptococci and suggests that xylitol has the potential to enhance inhibitory effects of low concentrations of fluoride.

Copyright © 2005 S. Karger AG, Basel

  Author Contacts

Nobuhiro Takahashi
Department of Oral Biology, Division of Oral Ecology and Biochemistry
Tohoku University Graduate School of Dentistry
4-1 Seiryo-machi, Aoba-ku, Sendai, 980-8575 (Japan)
Tel. +81 22 717 8294, Fax +81 22 717 8297, E-Mail nobu-t@mail.tains.tohoku.ac.jp

  Article Information

Received: October 4, 2004
Accepted after revision: February 18, 2005
Number of Print Pages : 8
Number of Figures : 4, Number of Tables : 0, Number of References : 49