Interpretation of bitewing radiographs: application of the kappa statistic to determine rater agreements.

The interrater agreement of 34 dentists in determining the presence or absence of caries and the depth of caries in bitewing radiographs was studied. The kappa statistic was used to determine rater agreement, and results indicate that there was substantial agreement on the presence or absence of caries and only fair agreement on the specific depth of caries. Because of the degree of disagreement in determination of the extent of caries among examiners, it is recommended that this fact be taken into account in relation to the findings on bitewing radiographs, particularly when there may be differences of opinion between parties.