A tremendous variation was found in time of eruption and in duration of eruption of permanent molars. This variation highlights the importance of individualizing caries preventive strategies for children.

This study examined the 2.5–year outcome of preventive programs – based on the Nexö method – offered to three groups of children from Solntsevsky, a district of Moscow. Study group A consisted of 45 3–year–olds, study group B of 50 6–year–olds, and study group C of 50 11–year–olds. A similar number of children were selected as control groups and they followed the normal dental service provided by the local Health Service System in the district. The caries–preventive programs offered to the study groups were based on: (1) education of the child, parents and teachers in the caries disease, (2) training in toothbrushing. In addition, the children in study groups B and C were offered professional plaque removal, applications of sodium fluoride (2%) and sealant applications according to individual needs. The children in groups B and C were clinically examined in March 1994 (baseline) after 1 and 2.5 years, respectively. Because of the age of the children in group A, these children were only examined once, after the study had been completed. After 2.5 years the children in all three study groups had improved their oral health status significantly compared to the children in the control group. The caries experience among the children in study group A was about half of that observed among children in the control group (4.91 def–s versus 8.60 def–s). The program was highly effective in controlling dental caries in the permanent dentition among the children in the study groups, who finished with a mean DMF–S of 0.28 (group B) and 3.12 (group C) compared to 2.24 and 6.35 among the children in the corresponding control groups. Nearly all the children used fluoridated toothpaste. The mean number of visits to the clinic decreased from year 1 to year 2 (5 versus 3.4 in study group B and 4.5 versus 3.3 in study group C). In conclusion, the preventive programs were highly effective with regard to improving the level of oral hygiene, and thereby reducing or even controlling the plaque–induced disease activity.

This study assessed the effectiveness and performance of a non-operative caries treatment programme (NOCTP) used since 1987 in the municipality of Nexö in Denmark. The NOCTP emphasizes mechanical plaque control and considers the eruption period of molar teeth as a risk factor. The mean DMF-S among 18-year-olds in 1999 and 2000 in Nexö was 1.23 ± 2.26 and 1.25 ± 2.01 (medians 0); 55 and 56% had DMF-S = 0. The mean numbers of sealed surfaces were 4.6 ± 3.25 and 4.0 ± 3.22, respectively. The cost per child per year was marginally and significantly reduced in the years with the NOCTP compared to that before 1988 (p = 0.05). In 4 comparison municipalities with very low caries experience, mean DMF-S scores among 18-year-olds in 1999 were 2.73–3.25 (medians 1–2) and were significantly higher than in Nexö (p < 0.001). The NOCTP differed from the preventive programmes used in the comparison municipalities in the period 1988–1999 in emphasising care for the erupting molars, the use of a firm guideline and stated goals to be achieved, but with less emphasis on diet. The effectiveness and performance of the NOCTP were both considered high, as very low DMF-S and high %DMF-S = 0 had been achieved by 1999, and 18-year-olds in Nexö had significantly less caries than in the comparison municipalities. The latter difference could not be explained by difference in caries-related background variables.

This investigation sought to estimate the influence a number of variables had on the inter-municipality variation in caries experience across Denmark. Unit of measurement was the municipality with public clinics. Mean DMF-S and %DMF-S = 0 of 15- and 18-year-olds in 1999 were obtained from 204 and 143 municipalities, respectively, out of a total number of 206 municipalities with public clinics. The independent variables were: cost per child per year; children/dentist ratio; auxiliary personal/dentist ratio; fluoride concentration in the water supply [F]; average personal income; % of mothers of the 15- and 18-year-olds with ≤10 years education (EDU-15 or EDU-18); proportion of immigrants; and size of the municipality. Multiple regression analyses disclosed that [F] (p < 0.001) and EDU-15 (p < 0.001) were significant variables among the 15-year-olds explaining 45% of the variation in mean DMF-S and 31% of the variation in % DMF-S = 0. With respect to the 18-year-olds, [F] (p < 0.001) and average personal income (p < 0.001) explained 53% of the variation in mean DMF-S and 30% of the variation in %DMF-S = 0. Few municipalities were characterized as outliers with significantly lower or higher observed caries experience than expected. It is concluded that there is room for other explanatory factors – first and foremost the professional effort made in the individual Public Dental Health Service to control caries.

The inter-municipality variation in mean DMFS 1999 was 0.88 to 8.73 and in 2004 was 0.56 to 6.19. The analyses found that fluoride level of the drinking water and mothers' length of education were significant variables explaining about 44% of the variations in mean DMFS in both years. Only one municipality was characterized as a positive outlier in 1999 as well as in 2004. The dose-response relations between increasing fluoride concentrations in the water supply and DMF-S values diminished in both years at a level above 0.35 ppm. The structured interview disclosed that municipalities with significant improvement in mean DMFS from 1999 to 2004 had established goals and were committed to the prevention of dental caries at the individual level. Instability in manpower; number of children in the service and economy was associated to municipalities with negative changes in caries experience.