The relation between 6-n-propylthiouracil sensitivity and caries activity in schoolchildren.

Caries activity tests are being used to assess caries risk in children. In recent years the purpose of most studies has been to develop practical, quick, reliable and economic tests. Clinical studies showed that the difference in sensitivity to the bitter taste of 6-n-propylthiouracil (PROP) is a heritable trait and may influence children's nutritional habits and caries development. The aim of this study was to investigate the relation between PROP sensitivity and caries activity in schoolchildren, in comparison with different caries activity tests. One hundred and twenty children aged between 7 and 12 years (mean age 9.97 ± 1.59) were investigated to determine socioeconomic status and oral hygiene habits, fluoride consumption, DMFT, DMFS, df, dfs, plaque indexes, and nutritional habits. Children were divided into three groups according to their caries risk status based on the Cariogram. The solution test and the PROP-impregnated filter paper test were used together to determine PROP sensitivity. After all associated factors had been controlled, stepwise regression analyses revealed that DMFT and dfs scores were important determinants of PROP. According to dfs, the sensitivity of the Cariogram and of PROP tests was 0.85 and 0.70, respectively, and specificity was 0.32 and 0.33, respectively. There was an inverse significant relationship between PROP sensitivity and DMFT, DMFS, and dfs results (p < 0.01). In conclusion, PROP nontasters were significantly more likely to have high caries risk than PROP tasters (p < 0.01).