Radiographic interpretation of endodontic file length

The purpose of this study was to evaluate the accuracy of examiners when asked to make file length adjustments with only a radiograph. The examiners viewed several radiographs under proper viewing conditions but without the aid of measuring devices. Two files of varying lengths (sizes 10 and 15) were placed in maxillary and mandibular premolars and molars from cadavers. The nine examiners were 67.91% in agreement of actual file length adjustment needed when adjustments of up to 0.5 mm were needed, 17.76% when adjustments of from 0.5 up to 1.0 mm were needed, and 14.33% when adjustments of greater than 1.0 mm were needed.