Urban-rural differences in dental caries experience among 6-year-old children in the Russian north.

INTRODUCTION Russians residing in rural areas, particularly in the north, have poorer health in general and lower life expectancy compared with urban residents. Little is known about dental health in the north of Russia, given that the last national oral health survey was performed more than 10 years ago. The aim of this study was to estimate the prevalence and experience of dental caries among 6-year-old children in a remote region in Northwest Russia. METHODS In total, 532 children aged 6 years were recruited in 5 randomly selected rural and urban settings of the Arkhangelsk region. Girls comprised 50.8% of the sample. Caries experience was assessed at D3 (cavitation) level by a single calibrated examiner. The prevalence of caries was calculated as the number of children with at least one affected tooth (decayed or missing or filled) divided by the number of examined children x 100% with 95% confidence intervals (CI). Caries experience was estimated using a sum of decayed, missing, filled teeth (dmft index) and presented as means and 95% CIs. Dichotomous and continuous data were analysed using Χ² and Mann-Whitney tests, respectively. RESULTS The prevalence of caries was 93.4% (95% CI: 90.9-95.2) with a mean dmft of 6.71 (95%CI: 6.37-7.04). On average, there were 5.48 (95% CI: 5.16-5.80) decayed, 0.44 (95% CI: 0.37-0.51) missing and 0.79 (95% CI: 0.67-0.91) filled teeth. Although the overall caries experience was similar in rural and in urban areas (6.52 vs 6.41, p=0.742), the number of decayed teeth in rural areas was greater (5.94 vs 4.91, p=0.001). Moreover, there were fewer missing teeth (0.31 vs 0.59, p<0.001) and filled teeth (0.45 vs 1.19, p<0.001) in rural areas. Boys had a greater number of affected teeth than girls (7.12 vs 6.32, p=0.023). CONCLUSIONS The levels of both caries prevalence and caries experience in the region exceeded the Russian average and corresponding levels in most European countries. Both urban-rural and sex variations in caries experience and its components were observed. Urgent preventive dental public health measures on both population and individual levels are needed to improve the situation.