On dental health in Icelandic children. Observations during a clinical dentifrice trial

Dental health and the relative caries preventive effect of different fluoride dentifrice formulations were assessed in an Icelandic child population. For a cross sectional study 1370 children, aged 11 and 12 years were examined for caries and periodontal conditions employing standardized methods. Longitudinal data were obtained from 1161 children, participating in a three-year dentifrice trial. Randomly selected subgroups were employed to study salivary levels of mutans streptococci and lactobacilli, consumption of high-sucrose products and enamel fluoride content in relation to caries experience. Relative caries preventive effect of anticalculus agents (HEBP and AHBP) and lowered fluoride concentration (250 ppm) in dentifrices were evaluated in a three-year double blind randomized clinical trial. At the baseline examination a comparatively high mean caries prevalence (DFS 9.9) was registered. Longitudinal observations showed a mean caries increment of 10.5 surfaces during a three-year period. Simultaneously an improvement of gingival health was observed. A majority of children harbored mutans streptococci (98%) and lactobacilli (92%). High numbers of either microorganism were associated with high caries prevalence. S. sobrinus carriers were more frequent among children with high numbers of CFU per ml saliva. The consumption of sugar-containing products was generally frequent. Higher caries increment was associated with consumption of sweets and bakery products during mealtimes. The fluoride content of surface enamel was comparatively low, reflecting scarce post eruptive exposure. Dentifrice, containing 250 ppm fluoride showed significantly lower caries preventive effect compared to 1000 ppm sodium fluoride and MFP formulations. Addition of anticalculus agents (biphosphonates) had no negative effect on reducing caries increment. These studies show that dental caries constitutes a major health problem among Icelandic children, where high sugar consumption and comparatively low exposure to fluoride appear to play major roles. The use of fluoride dentifrice has not been able to limit caries development.