Xeroradiography in root fracture diagnosis.

Root fracture is a clinical problem that often is difficult to diagnose. The purpose of this study was to compare diagnostic value of conventional radiographic and xeroradiographic images of experimentally fractured teeth. Forty-five extracted human single-rooted teeth were used. The roots of the teeth were coated with wax to simulate periodontal ligament and invested in acrylic to the cementoenamel junction. An access cavity was prepared and para-post, size 4 to 12 mm, was placed into the root canal. Each tooth with post was placed on the load cell table of an Instron testing machine. The Instron continuously recorded load on a moving graph paper. The load was increased until the tooth fractured. Determination of fracture was made by the sound of a sharp "crack" and by a sudden release of load on the post, as seen on the Instron recording graph. After fracture, conventional radiograph and xeroradiograph were obtained for each tooth by use of the paralleling technique. The x-ray beam angle, film distance, and tooth placement were held constant in both techniques by use of a Rinn instrument. All films were evaluated by use of light from a masked viewbox, while all of the xeroradiographs were viewed in reflected light. A magnifying glass was used to aid in the examination process. The samples were examined and categorized for root fracture by the examiners with the use of the following scores: 0 = unacceptably poor, 1 = poor but diagnostic, 2 = adequate for diagnostic information, and 3 = optimal for diagnostic information.(ABSTRACT TRUNCATED AT 250 WORDS)