How much does the DMFT index underestimate the need for restorative care?

The DMFT index, which represents caries experience as recommended by the World Health Organization (clinical examination without radiographs), was compared with a modified DMFT index with radiographs. The purpose was to evaluate how much the DMFT index underestimates the need for restorative care. A cohort of 376 young adults (eighteen to twenty years old) was examined from March 2003 to December 2004. Dental screening was based on clinical examination and bilateral bitewing radiographs. DMFT index was calculated with and without radiographs to compare DMFT scores. The average DMFT was 1.42 higher with radiographs than without (6.35 vs. 4.93, respectively), and the D component was 1.75 higher. The Pearson correlation between DMFT indices was 0.899 (p<0.0001) and 0.759 between the D components (p<0.0001). A correlation was found between D with radiographs and smoking more than ten cigarettes per day (p=0.0069). Without radiographs, there is a 44 percent probability that the caries decay value will be lower than the actual value, thus causing a greater possibility of diagnostic errors. The findings indicate that assessing treatment needs for a population based only on DMFT screening is inadequate and incomplete without radiographs.