An in vitro investigation of developmental defects of enamel under wet and dry conditions.

Disagreement exists amongst investigators as to whether or not teeth should be dried before they are examined for developmental defects of enamel. To determine if results are affected by drying of the teeth, 91 extracted premolars and first permanent molars were examined first wet, and then again 1 week later after drying. Following removal of loose debris with an explorer, the enamel defects that were present were categorised according to a modified version of the FDI (DDE) Index. The drying of the surface of the tooth by compressed air allowed a more detailed and precise examination to be performed because the nature and extent of the defects were easier to see. This resulted in diffuse opacities being diagnosed in 144 (52.7 percent) of the tooth regions when the teeth were wet, and 161 (60.0 percent) after drying. The level of reproducibility of diagnosis was higher under dry conditions. It was easier to determine the colour of the teeth using a colour guide than without this assistance. These findings indicate that it is important that investigators performing clinical surveys on the prevalence of defects of enamel should clearly specify whether the teeth were examined wet or dry.