Collaborative WHO xylitol field studies in Hungary. VI. Changes in the carbohydrate to protein ratio of dental plaque.

The carbohydrate to protein ratio of dental plaque was analyzed in a field study assessing the effect of partial substitution of dietary sucrose by xylitol (X group) in comparison with systemic fluoride (F group) and restorative treatment solely (C group). The biochemical analysis was supplemented by quantitative assessment of plaque through the visible plaque index (VPI). The present substudy was carried out cross-sectionally and longitudinally (n = 83) in initially 6- to 11-year-old children. Missing base-line values for the carbohydrate to protein ratio were partly compensated for through reexamination of the carbohydrate to protein ratio 15 months after termination of the trial. The latter series served as reference to indicate the base-line situation. A lower carbohydrate to protein ratio was measured in the X and F groups than in the C group. Improvement of the VPI values was obtained only in the X group. Our results suggest the potential value of parallel quantitative and qualitative assessment of plaque.