Comparison of enamel defects in the primary and permanent dentitions of children from a low-fluoride District in Australia.

PURPOSE: The purpose of this study was to compare developmental defects of enamel (DDE) in the primary and permanent dentitions of children from a low-fluoride district. METHODS: A total of 517 healthy schoolchildren were examined using the modified DDE criteria. RESULTS: The prevalence of DDE in the primary and permanent dentition was 25% and 58%, respectively (P<.001). The mean number of teeth with enamel opacity per subject was approximately threefold compared to that affected by enamel hypoplasia (3.1±3.8 vs 0.8±1.4, P<.001 in the primary dentition and 3.6±4.7 vs 1.2±2.2, P<.001 in the permanent dentition). Demarcated opacities (83%) were predominant compared to diffuse opacities (17%), while missing enamel was the most common type of enamel hypoplasia (50%), followed by grooves (31%) and enamel pits (19%) (P=.04). In the permanent dentition, diffuse and demarcated opacities were equally frequent, while enamel grooves were the commonest type of hypoplasia (52%), followed by missing enamel (35%) and enamel pits (5%; P<.001). CONCLUSIONS: In a low-fluoride community, developmental defects of enamel were twice as common in the permanent dentition vs the primary dentition. In the primary dentition, the predominant defects were demarcated opacities and missing enamel, while in the permanent dentition, the defects were more variable.