Supplementary Material for: Impact of medical and surgical obesity treatment on dental caries: A two-year prospective cohort study

The objective was to study the long-term effects on oral health of bariatric surgery compared with medical treatment of obesity. Swedish females with morbid obesity (n = 66;18-35 years at baseline) were followed prospectively from before obesity treatment until two years after treatment. The main response variable was dental caries registered according to the ICDAS-II system. Possible confounding caused by sociodemographic characteristics, general health, oral health habits and oral hygiene was controlled for. The statistical methods included Chi-square tests, Student’s t-tests, one-way ANOVA, Wilcoxon’s non-parametric tests and linear regression models. In the surgically treated patients (n = 40), a significant increase over time in enamel caries (mean increase 4.13 tooth surfaces ICDAS1-2), dentine caries (mean increase 2.18 tooth surfaces ICDAS3-6), and total caries (mean increase 6.30 tooth surfaces ICDAS1-6) was registered (all p < 0.001), which was not seen in the medically treated patients (n=26). However, the difference between the treatment groups (surgical or medical) was only statistically significant for enamel caries (crude β 4.89, p=0.003) and total caries (crude β 6.53, p<0.001). The relationships were stable and independent of differences in confounders as socioeconomy, general health and oral health behaviors. In conclusion, two years after obesity treatment, a significant increase in dental caries was registered in the surgically treated but not in the medically treated women. The dental service should intensify its preventive efforts in individuals undergoing obesity treatment.