Observer agreement in the detection of proximal caries with direct digital intraoral radiography.

Abstract Objective. The aim of this study was to compare several values for consistency obtained by charged-coupled-device-based direct digital intraoral radiography with those obtained by conventional film-based radiography to evaluate observer agreement in determining the depth of proximal caries. Study design. A total of 93 proximal surfaces on radiologic images that were obtained by both the conventional film-based bitewing technique and by direct digital intraoral radiography were evaluated by six observers. One of these observers also evaluated the same images six months after the initial evaluation. The kappa value, consistency ratio, agreement ratio, and Kendall's correlation coefficient were calculated for interobserver and intraobserver agreement. Results. The overall kappa values for interobserver agreement were 0.439 and 0.424 in the direct digital system and the film-based radiography, respectively. The depth-related change of the values showed similar patterns in the two modalities for both interobserver and intraobserver agreement. Conclusion. The digital intraoral system resulted in no deterioration in observer agreement, and it presents no problems for clinical use with respect to the reliability of diagnosis.