The educational gradient in dental caries experience in Northern- Norway: a cross-sectional study from the seventh survey of the Tromsø study

Background Although, studies from Norway indicate a reduction in dental caries experience, in Northern-Norway this non-communicable oral condition is still prevalent. There is conflicting evidence of presence of social inequalities in dental caries in an adult population. Therefore, the aim of this study was to assess an association between educational level and dental caries experience in adults in urban Tromsø municipality, Northern-Norway, using The World Health Organization (WHO) Commission on Social Determinants of Health (CSDH) framework of health determinants. Methods Data from 3752 participants having recorded dental caries status and educational level in the seventh survey of the Tromsø Study: Tromsø7 were included. Dental status was examined clinically as decayed-, missing-, filled-teeth (DMFT score). For statistical analyses DMFT score was grouped into lower (DMFT<19) and higher (DMFT≥20). Educational level was obtained from a questionnaire and categorized as primary/partly secondary education, upper secondary education, tertiary education, short and tertiary education, long. Data on social and intermediary determinants was also self-reported. Univariable and multivariable binary logistic regression analyses were applied. Result This study included 1939 (52%) women and the mean age of the participants was 57.11. The mean DMFT score was 18.03. The odds of having higher DMFT score followed a gradient based on educational level. Participants who reported lower than secondary education had 2.06 -fold increased odds of having higher DMFT score than those with tertiary education, long (OR: 2.06, 95% CI: 1.50–2.83). Those with upper secondary education had 60% higher odds of having higher DMFT score (OR: 1.60, 95% CI: 1.21–2.11), and those with tertiary education, short had 66% higher odds of having higher DMFT score (OR: 1.66, 95% CI: 1.24–2.22). Conclusion The current cross-sectional study suggested an educational gradient in dental caries experience in an adult population of Northern- Norway. Further studies validating our results and investigating mechanisms of educational inequalities in oral health are warranted

Educational gradient in dental caries

Background: Dental health is an important aspect and a key indicator of general health. However, detailed data on dental health in the adult population in Norway is lacking. Literature indicates that people with lower socioeconomic position (SEP) have significantly poorer dental health than people with higher SEP. For example, adults in Norway with higher education report better self-reported dental health status compared with adults who have lower education. Therefore, although the inequality in dental health has been significantly reduced in Norway the last 50 years, findings may indicate that there still exists inequality in dental health among adults in Norway. These inequalities often manifest in a gradient. Aim: This study sought to investigate if educational gradient in dental caries exists in the adult population in Tromsø municipality. The objective was to assess an association between educational level and dental caries experience among the participants of the Tromsø 7 study. Materials and methods: The study population consisted of 3823 adults living in Tromsø municipality in northern- Norway who participated in the Tromsø 7 study. Social determinants: education, age, sex, household income, spouse, childhood financial situation, mother and fathers’ education, siblings, and intermediary determinants: smoking, alcohol consumption, exercise, soft drinks, tooth brushing, fluoride toothpaste, interdental cleaning aids, fluoride tablets, fluoride rinse, dental care and dental satisfaction was self-reported in a questionnaire. Registration of decayed, missing, filled, teeth (DMFT) score was performed after the clinical examinations by calibrated dentists using bitewing radiographs and intra-oral clinical photographs. Descriptive statistics, chi- square test and independent t-test was performed to describe the sample. Univariable and multivariable binary logistic regression models were conducted and the association between educational level and DMFT score was adjusted for selected social and intermediary covariates. Results: After excluding participants with missing values in education and DMFT score, the data of 3752 participants aged 40- 92 years was analyzed. The median DMFT score among all participants was 19 (9), mean 18.03 (6.41). The univariable binary logistic regression analysis showed a statistically significant association between educational level and DMFT score.The odds for higher DMFT score followed a gradient based on educational level, meaning that the odds for higher DMFT score were observed in lower education level (primary/partly secondary education level versus tertiary education level, long) and lower odds for higher DMFT score were in higher education level (upper secondary level and tertiary education, short versus tertiary education, long). When adjusted for covariates a statistically significant association remained between education level and DMFT score. However, the educational gradient was not clearly observed between the two intermediate educational levels. Conclusion: The present cross-sectional study demonstrated an educational gradient in dental caries among the adult population in Tromsø municipality. The results call for health promotion and disease prevention initiatives to address this social determinant and thereby reduce educational inequalities in dental health