Endodontic radiography - what's displaying the radiograph? The yield of commercial computer screens vs. DICOM calibrated medical screens in endodontic radiography.

OBJECTIVE: A comparison between commercial computer screens and DICOM-calibrated medical screens for characterizing anatomy and diagnosing dental pathologies was performed. The aim of this study was to evaluate and compare the ability of each of those screens to identify root apices and widening of the periodontal ligament (PDL) in the posterior maxillary area. MATERIALS AND METHODS: Digital X-ray images of 53 maxillary molar teeth were examined by means of a commercial computer screen and again two months later with a DICOM screen to compare their ability to help identify and diagnose PDL widening and to locate the root apices of those teeth. RESULTS: The DICOM screen had a significantly better ability to identify widened PDLs (from 31.4% to 34.8% of the cases compared to 19% to 26.1% for the commercial screens, P < .001), depending upon the observer. The DICOM screen was also significantly superior in depicting the root apices compared to the commercial screens (from 77.4% to 83.6% of the cases compared to 56% to 66.7% for the commercial screens, P < 0.001), depending upon the observer. CONCLUSION: DICOM-calibrated medical screens were significantly superior to commercial computer screens for identifying widened PDLs and locating the root apex in the posterior maxillary area.

The ability of different compositions of calcium silicate and epoxy sealers to withstand gutta percha removal via in vitro pull-out testing.

OBJECTIVE: examination of the influence of chemical composition changes on the ability of sealers to withstand a pull-out test. MATERIALS AND METHODS: Fifty distal or palatal canals of extracted teeth were prepared by Dc Taper files. The teeth were divided into five groups: AH Plus, BJM RCS, Total Fill BC,AH Plus Bioceramic and a group with Gutta Percha with no sealer added. Ten days after obturation, each cone was subjected to the "pull-out test" with the Shimadzo Universal Testing Machine until it was torn or removed from the canal. A force to Stroke graph was generated and the maximum vertex of this graph was recorded. The number of times the cone was torn or removed was recorded. RESULTS: The amount of force needed to remove or rupture the cone was significantly higher in all sealer groups compared to the AH Plus Bioceramic group. The force needed for the AH Plus group was double that needed for the AH Plus Bioceramic group 4 (1.87 ± 0.53 N vs 0.93 ± 0.48 N, respectively, P < 0.001). All of the cones (n = 10) in the AH Plus Bio Ceramic Sealer group were removed in their entirety (P = 0.01 compared to each of the other groups). CONCLUSIONS: The addition of macromolecules to epoxy sealer does not change the material's ability to withstand the pull-out test. Decreasing the amount of tri- and di-calcium silicate compounds combined with increasing amounts of zirconium oxide in a Bioceramic sealer significantly decreased the material's ability to withstand the pull-out test.