Caries pattern in primary molars in Dutch 5-year-old children

Aim: The aim of this study was to investigate the difference in caries prevalence based on quadrant dmfs data between first and second primary molars in 5-year-old Dutch children. Study design: Cross-sectional observational study. Methods and statistics: For this study 692 children, all insured by a Health Insurance Fund, living in one of four selected cities in The Netherlands were asked to participate in the study. From the original cohort 435 children (49% girls) participated. Clinical examinations were performed and only carious lesions with involvement of the dentine were reported. Lesions on the occlusal, buccal, palatal/lingual, mesial and distal surfaces as well as lesions in buccal and palatal pits and fissures were reported separately. No radiographs were taken. Systematic differences in dmfs between first and second molars in the same quadrant of each primary dentition were tested with the Wilcoxon signed rank test. Results: Second primary molars, even after correction for caries in pits and buccal/palatal fissures, had a statistically significant higher total dmfs than the first primary molars. The differences were mainly found on the occlusal surfaces. On proximal surfaces, the first primary molars had significant more caries than the second primary molars. The d-component constituted the major part of the caries index. Conclusions: Second primary molars, corrected for decay in the pits and buccal/palatal fissures of this molar, are more affected by caries than first primary molars and that the differences in caries prevalence are the largest on the occlusal surface. The specific site of the caries found suggests that developmental disturbances in second primary molars may attribute to their prevalence.