OO ABSTRACT RESUMO EFFICACY OF THREE CONDITIONS OF RADIOGRAPHIC INTERPRETATION FOR ASSESSMENT ROOT CANAL LENGTH

bjective: To compare the efficacy of three conditions of image interpretation for radiographic root measurements and calculating the intra-observer reproducibility of the measurements. Material and methods: Thirty intra-operative periapical radiographs of maxillary central and lateral incisors were measured, in mm, from the tip of the file to the radiographic apex, using a caliper. Three separate measurements were made of the 30 radiographs. The three measurements for each tooth were averaged and the mean used for further calculations. After a 12-day period, the measurements were repeated. The three experimental viewing conditions used: 1) standard viewbox without masking of background light around the radiograph and without magnification (Visual); 2) standard viewbox with use of a magnifying lens of 2.5x and with background light masked (Magnification); and 3) viewer device that restricts room lighting and enlarges the image by a magnifying lens of 1.75x (Viewer). The mean and standard deviation of the measurements were calculated and used for descriptive analysis. Two-wa