Caries decline before fluoride toothpaste was available: earlier and greater decline in the rural north than in southwestern Norway

The purpose of this study was to evaluate factors related to caries in 6-17 -year-olds in 2 groups of Norwegian counties between 1966 and 1983. The ave rage number of surfaces filled and permanent teeth extracted due to caries declined in the 4 northern counties From 1967. An increase was recorded in the 7 southwestern counties until 1971, then a decline. In the 1960s signif icantly more surfaces were filled and teeth extracted in the north compared to the southwest. Based on intra-county comparisons, the decline in surfac es treated was greater in the north between 1967 and 1983; 5.4 +/- 0.4 vs 3 .7 +/- 0.7, P < 0.01. The averages were 1.9 surfaces treated in the north a nd the southwest in 1983. Higher infant mortality, lower percentage of peop le with completed senior secondary education, and more inhabitants per doct or and per dentist in the north indicate a less favorable situation than in the southwest. School-based fluoride programs had been implemented in both groups from the mid-1960s and around 60% participated when fluoride toothp aste became freely marketed in 1971. More fluoride programs and more fluori de tablets were available ro children in the north; this may indicate a pre ventive attitude among dentists. The decline of caries started at different times in different Darts of Norway. In the rural north with the most unfav orable situation, the decline was greater and started years before fluoride toothpaste came on to the market. The early decline may partly be ascribed to the school-based fluoride programs, the continued decline to several fa ctors.